Changes

<div style="background-color: #fff0f0; border: 1px solid black; padding: 1ex; margin: 1ex; margin-right: 24em; min-width: 20em;">The genus of ''Lactobacillus'' has recently been broken up into 25 different genera. Portions of this wiki may still refer to the old nomenclature until we can make all the updates. For the purposes of this wiki, all new genera that were once considered to be ''Lactobacillus'' will remain on this wiki page for the foreseeable future. Abbreviations will remain the same; for example ''Lactiplantibacillus plantarum'', previously ''Lactobacillus plantarum'', is still abbreviated as ''L. plantarum''. Also note that yeast labs and probiotics manufacturers may not update their product brands to reflect the new scientific nomenclature. See [[Lactobacillus#Recent_Taxonomy_Changes|''Lactobacillus'' Recent Taxonomy Changes]] for more information. </div> '''''Lactobacillus''''' (often referred to by brewers as "Lacto") is a genus of Gram-positive, rod-shaped lactic acid bacteria (LAB) which produces acidity and sour flavors in the form of lactic acid and [[Lactobacillus#Sugar_Utilization_and_Secondary_Metabolites|secondary metabolites]] found in lambics, Berliner Weiss, sour brown ales, and gueuze. All ''Lactobacillus'' species are facultative anaerobes, which means they grow anaerobically but can also grow in the presence of oxygen and use oxygen to some degree <ref name="todar_lactics4"></ref>. They [https://www.researchgate.net/post/How_to_prepare_spore_forming_media_for_lactobacillus do not form spores]. There are more than 100 species, many of which are found in the human gastrointestinal track <ref name="todar_lactics4">[http://textbookofbacteriology.net/lactics_4.html ''Lactic Acid Bacteria''. Todar's Online Texbook of Bacteriology. Kenneth Todar, PhD. Pg. 4. Retrieved 07/28/2015.]</ref><ref name="Todar_nutgro4">[http://textbookofbacteriology.net/nutgro_4.html ''Nutrition and Growth of Bacteria''. Todar's Online Texbook of Bacteriology. Kenneth Todar, PhD. Retrieved 07/28/2015.]</ref>. In addition to beer, some species of ''Lactobacillus'' are also used to ferment yogurt, cheese, sauerkraut, pickles, wine, cider, kimchi, cocoa, and kefir <ref>[https://en.wikipedia.org/wiki/Lactobacillus ''Lactobacillus''. Wikipedia. Retrieved 07/28/2015.]</ref>. ''Lactobacillus'' can form a [[pellicle]] (need reference). See ''[[Pediococcus]]'', ''[[Brettanomyces]]'', ''[[Saccharomyces]]'', [[Mixed Cultures]], [[Kveik#Commercial_Availability|Kveik]], and [[Nonconventional Yeasts and Bacteria]] charts for other commercially available cultures. See the [[Sour WortingWort Souring]] and [[Mixed Fermentation]] pages for brewing techniques with ''Lactobacillus''. See the [[Alternative Bacteria Sources]] section for culturing ''Lactobacillus'' from grains, yogurt, probiotics, and other sources. ==Introduction of Characteristics and Taxonomy==''Lactobacillus'' is a genus of bacteria that are considered to be a part of a broader classification of bacteria known as ''lactic acid bacteria'' (abbreviated as "LAB"). Other genera of bacteria that belong to this group and also appear in food fermentation include ''Lactococcus'', ''Streptococcus'', ''Pediococcus'', and ''Leuconostoc''. ''Lactobacillus'', as well as these other LAB genera, have three main metabolic pathways: glycolysis (fermentation of sugars), lopolysis (degradation of fat), and proteolysis (degradation of proteins). Lactic acid (specifically the conjugate base form, lactate), is the major byproduct of their fermentation. Other secondary metabolites include diacetyl, acetoin, acetaldehyde or acetic acid (some of which can contribute yogurt flavors to yogurt as well as maybe beer). While the lopolysis pathway contributes little to flavor, the proteolysis pathway produces amino acids which can be further converted into various alcohols, aldehydes, acids, esters, and sulphur compounds, many of which contribute various flavors to dairy fermentation products as well as to sour beer <ref name="Bintsis_2018">[http://www.aimspress.com/article/10.3934/microbiol.2018.4.665/fulltext.html Lactic acid bacteria as starter cultures: An update in their metabolism and genetics. Thomas Bintsis. 2018. DOI: 10.3934/microbiol.2018.4.665.]</ref>.  The genus ''Lactobacillus'' contains a large number of relatively diverse species, and is the largest genus of the lactic acid bacteria group with over 50 species <ref>[https://web.archive.org/web/20070202132806/http://www.bacterio.cict.fr/l/lactobacillus.html List of Prokaryotic Names with Standing in Nomenclature - Genus Lactobacillus. J.P. Euzéby. Archive.org Wayback Machine; Feb 02, 2007.]</ref>, many of which have been identified as playing an important role in food fermentation or as probiotic species found in the human gut. The species ''Lactobacillus delbruekii'' consists of three subspecies: subsp. ''delbrueckii'', subsp. ''lactis'' and subsp. ''bulgaricus'', and have been used in yogurt fermentation. ''L. plantarum'' has one of the largest genomes among LAB. ''L. sanfranciscensis'' is the predominant LAB in sourdough cultures. ''Lactobacillus paracasei'' subsp. ''paracasei'', ''L. plantarum'', ''L. curvatus'', ''L. rahmosus'', and ''L. casei'' are often found in cheese maturation. ''L. johnsonii'' and ''L. reuteri'' strains have mostly been found in human and animal feces, suggesting that they are natural intestinal flora and are probiotic. Other species that have been used as probiotics include ''L. fermentum'', ''L. plantarum'', ''L acidophilis'' (the latter is also used in yogurt fermentation). ''Lactobacillus sakei'' subsp. ''sakei'' is used in the fermentation of sake <ref name="Bintsis_2018" />. Many of the previously mentioned species are purchased from yeast labs and used intentionally by brewers making sour beer (see [[Lactobacillus#Culture_Charts|Culture Charts]] below). ''L. acetotolerans'' has recently been claimed to also be found in many mixed fermentation sour beers, specifically in spontaneously fermented sour beers <ref>[https://www.sciencedirect.com/science/article/pii/S0740002020302471? Alexander Tyakht, Anna Kopeliovich, Natalia Klimenko, Daria Efimova, Nikita Dovidchenko, Vera Odintsova, Mikhail Kleimenov, Stepan Toshchakov, Alexandra Popova, Maria Khomyakova, Alexander Merkel. Characteristics of bacterial and yeast microbiomes in spontaneous and mixed-fermentation beer and cider, Food Microbiology. Volume 94, 2021, 103658.ISSN 0740-0020. https://doi.org/10.1016/j.fm.2020.103658.]</ref><ref>[https://www.biorxiv.org/content/10.1101/2021.07.21.453094v1 Mixed culture metagenomics of the microbes making sour beer. Renan Eugênio Araujo Piraine, Fábio Pereira Leivas Leite, Matthew L. Bochman. bioRxiv 2021.07.21.453094; doi: https://doi.org/10.1101/2021.07.21.453094.]</ref> (see also [https://www.facebook.com/groups/592560317438853/search/?q=acetotolerans MTF threads]). ===Recent Taxonomy Changes===Recently, whole genome sequencing led to the genetically driven proposal to divide the genus of ''Lactobacillus'' into either 2 subdivisions, or more radically into 10-14 subdivisions by one study <ref>[https://aem.asm.org/content/84/17/e00993-18 Comparative Genomics of the Genus Lactobacillus Reveals Robust Phylogroups That Provide the Basis for Reclassification. Elisa Salvetti, Hugh M. B. Harris, Giovanna E. Felis, Paul W. O'Toole. 2018. DOI: 10.1128/AEM.00993-18.]</ref><ref>[https://aem.asm.org/content/85/3/e02155-18 Towards a Genome-Based Reclassification of the Genus Lactobacillus. Stijn Wittouck, Sander Wuyts, Sarah Lebeer. 2019. DOI: 10.1128/AEM.02155-18.]</ref> and 23 divisions by another study accepted for publication by the International Journal of Systematic and Evolutionary Microbiology which tends to carry more authority in microbiological circles <ref name="Zheng_2020">[https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.004107 A taxonomic note on the genus Lactobacillus: Description of 23 novel genera, emended description of the genus Lactobacillus Beijerinck 1901, and union of Lactobacillaceae and Leuconostocaceae. Jinshui Zheng et al. 2020. DOI: https://doi.org/10.1099/ijsem.0.004107.]</ref>. With the emergence of whole genome sequencing, other changes have been proposed, such as merging and splitting species of ''Lactobacillus'' <ref>[https://www.biorxiv.org/content/biorxiv/early/2019/01/31/537084.full.pdf A genome-based species taxonomy of the Lactobacillus Genus Complex. Stijn Wittouck, Sander Wuyts, Conor J Meehan, Vera van Noort, Sarah Lebeer. 2019. DOI: http://dx.doi.org/10.1101/537084.]</ref>. Renaming 200+ lactobacilli into new categories and names could also have a significant impact on the industries that use these microbes. The scale of this change has been discussed and considerations given for such industries, while the new classifications should be robust enough to withstand future scientific discoveries and should be based on genetic patterns <ref>[https://www.sciencedirect.com/science/article/pii/S0924224419303164 The potential impact of the Lactobacillus name change: the results of an expert meeting organised by the Lactic Acid Bacteria Industrial Platform (LABIP). Bruno Pot, Elisa Salvetti, Paola Mattarelli, Giovanna E. Felis. 2019. DOI: https://doi.org/10.1016/j.tifs.2019.07.006.]</ref>. Several species mergers and splits have also been identified <ref>[https://search.proquest.com/docview/2299499440?pq-origsite=gscholar A Genome-Based Species Taxonomy of the Lactobacillus Genus Complex. Wittouck Stijn; Wuyts Sander; Meehan, Conor J; van Noort Vera; Lebeer, Sarah. 2019. DOI:10.1128/mSystems.00264-19.]</ref>.  The outcome of these analyses has been to update the genus of ''Lactobacillus'' into 25 distinct genera, including 23 new genera. They now include: ''Lactobacillus'', ''Paralactobacillus'', ''Acetilactobacillus'', ''Agrilactobacillus'', ''Amylolactobacillus'', ''Apilactobacillus'', ''Bombilactobacillus'', ''Companilactobacillus'', ''Dellaglioa'', ''Fructilactobacillus'', ''Furfurilactobacillus'', ''Holzapfelia'', ''Lacticaseibacillus'', ''Lactiplantibacillus'', ''Lapidilactobacillus'', ''Latilactobacillus'', ''Lentilactobacillus'', ''Levilactobacillus'', ''Ligilactobacillus'', ''Limosilactobacillus'', ''Liquorilactobacillus'', ''Loigolactobacilus'', ''Paucilactobacillus'', ''Schleiferilactobacillus'', and ''Secundilactobacillus''. This [http://lactotax.embl.de/wuyts/lactotax/ Taxonomy Tool] can be used to check which species have changed. it is important to note that species names did not change, only the genus names changed for most species <ref name="Zheng_2020" />. The International Scientific Association for Probiotics and Prebiotics has also [https://isappscience.org/new-names-for-important-probiotic-lactobacillus-species adopted this new nomenclature].  Examples of changes made to typical brewing strains:{| class="wikitable sortable"|-! style=width:30em | Previous Name ! style=width:30em | New Name <ref name="Zheng_2020" />|-| ''Lactobacillus casei'' || ''Lacticaseibacillus casei''|-| ''Lactobacillus paracasei'' || ''Lacticaseibacillus paracasei''|-| ''Lactobacillus rhamnosus'' || ''Lacticaseibacillus rhamnosus''|-| ''Lactobacillus plantarum'' || ''Lactiplantibacillus plantarum''|-| ''Lactobacillus brevis'' || ''Levilactobacillus brevis''|- | ''Lactobacillus fermentum'' || ''Limosilactobacillus fermentum''|-| ''Lactobacillus reuteri'' || ''Limosilactobacillus reuteri''|-| ''Lactobacillus acetotolerans'' || Unchanged|-| ''Lactobacillus acidophilus'' || Unchanged|-| ''Lactobacillus delbrueckii'' || Unchanged|-| ''Lactobacillus helveticus'' || Unchanged|-|} For more information on the taxonomic changes to the ''Lactobacillus'' genus, see:* [https://www.facebook.com/groups/MilkTheFunk/permalink/3542631249098397/ Post in MTF about splitting the genus into 23 new groups.]* [http://lactobacillus.ualberta.ca Name changes supported by the International Journal of Systematic and Evolutionary Microbiology] and [https://isappscience.org/new-names-for-important-probiotic-lactobacillus-species/ this science news article]. For more information on the metabolism of lactobacilli, see [[Lactobacillus#Metabolism|Metabolism]].

! Lab Name !! Product Name !! Taxonomy !! CO2 Producer (HetHetero/HomHomo) !! Starter Note !! Fermentation/Other Notes|-| [[Bootleg Biology]]/[[Spot Yeast]] || Sour Weapon L || ''Lactiplantibacillus plantarum'' (blended strains) || Facultatively heterofermentative || || Drops the pH of wort quickly. At 98F, trial batches dropped the pH of wort to 3.0 after just 24 hours. When pitched at 84F, pH should reach 3.5 in 24 hours. Ideal to use for acidifying wort for quick/kettle sours, and is also very effective when co-pitched with a yeast strain. As with any Lactobacillus culture, we do not recommend using in worts with <s>10 or more IBUs</s> any hops (this is the up to date recommendation from Jeff Mello of Bootleg Biology; any amount of hops will inhibit ''L. plantarum'' in general) <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2800217156673147/?comment_id=2800400083321521&reply_comment_id=2804474432914086&comment_tracking=%7B%22tn%22%3A%22R%22%7D Jeff Mello. Milk The Funk Facebook thread on the lack of IBU tolerance of ''L. plantarum'' and Sour Weapon L. 07/23/2019.]</ref> as that will prevent significant souring. Isolated from traditional Norwegian Kveik <ref>[http://bootlegbiology.com/2017/06/27/new-culture-pre-sale-july-5-featuring-mtf-mega-blend-sour-weapon-l/ "New Culture Pre-Sale July 5: Featuring MTF Mega Blend & Sour Weapon L!" Bootleg Biology website. 06/27/2017. Retrieved 06/05/2017.]</ref>.|-| [[Brewing Science Institute]] || L. brevis || ''Levilactobacillus brevis'' || Heterofermentative || || Shipped during log phase, so recommended to use within 2 to 3 days of receiving. Unlike yeast, BSI sells bacteria by volume, and will sell a specific volume for the number of BBL's the brewer is souring. Store at room temperature, not cold. Optimal temperature for fermentation is 102-105°F. Bacteria is half the price of yeast. Commercial pitches only; not listed on their catalog, but is carried in stock. BSI does not have IBU tolerance data, but there has been at least one report of it being tolerant of up to 20 IBU <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2147198278641708/?comment_id=2147921045236098&reply_comment_id=2148812765146926&comment_tracking=%7B%22tn%22%3A%22R%22%7D John Rowley, Andrew Deming, and Dan Ramos. Milk The Funk Facebook group thread on BSI brevis. 06/26/2018.]</ref>.

| [[Bootleg BiologyBrewing Science Institute]] || Sour Weapon L . delbrueckii || ''Lactobacillus plantarum (blended strains) delbrueckii'' || Facultatively heterofermentative Homofermentative || || If you’re looking to drop the pH of wort as quickly and low as possible, Sour Weapon L is your go to Lacto blend. At 98F, we’ve had trial batches drop the pH of wort to 3.0 after just 24 hours. When pitched at 84F, pH should reach 3.5 in 24 hours. This is the ideal A Lactobacillus bacteria blend to use for acidifying wort for quick/kettle sours, and is also very effective when co-pitched with that produces a yeast strainclean lactic sourness. As with any Lactobacillus culture, we do not recommend using in worts with 10 or more IBUs as that will prevent significant souring. Isolated from from traditional Norwegian Kveik <ref>[http://bootlegbiology.com/2017/06/27/new-culture-pre-sale-july-5-featuring-mtf-mega-blend-sour-weapon-l/ "New Culture Pre-Sale July 5: Featuring MTF Mega Blend & Sour Weapon L!" Bootleg Biology website. 06/27/2017. Retreived 06/05/2017.]</ref>.

| [[Brewing Science Institute]] Chr. Hansen || L. delbrueckii Harvest LB-1 || Lactobacillus delbrueckii ''Lactiplantibacillus plantarum'' || Homofermentative Faculatative Heterofermentative || The culture is ready for inoculation directly in all beverage bases without previous reactivation (freeze dried) || A Lactobacillus bacteria that produces Harvest LB-1 is a freeze dried concentrated pure culture of ''L. plantarum''. The culture has been selected to ensure a clean lactic sournessfast and safe acidification of cereal bases, vegetable juices and other sugar beverage bases. Can acidify wort to pH 3.2 and should allow brewers to decrease pH from 5.5 to 3.5 in ~ 16 hours. Temp range of 70 – 100 ⁰F. Tolerates 8 IBU. Commercial only sizes available through [https://www.gusmerenterprises.com/catalog/brewing/brewing-processing-aids/sour-beer/harvest-lb-1/ Gusmer Brewing]. <ref>[https://www.gusmerbeer.com/wp-content/uploads/sites/8/2019/04/PI_GLOB_HarvestLB-1_718316_EN.pdf "Harvest LB-1". Chr. Hansen. Retrieved 12/19/2019.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/3140287979332728/?comment_id=3140612629300263&reply_comment_id=3140685999292926 Chris Webster. Sales at Gusmer. Milk The Funk Facebook thread on Chr Hanson L. plantarum. 12/19/2019.]</ref>

| [[Community Cultures Yeast Lab]] || Lactobacillus brevis || ''Levilactobacillus brevis'' || Heterofermentative || || For traditional and kettle souring methods, produces high lactic acid. Suggested for use in wort under 5-10 IBUs. Fermentation Temperature: 75-105F.|-| [[Community Cultures Yeast Lab]] || Lactobacillus Plantarum || ''Lactiplantibacillus plantarum'' || Facultatively heterofermentative || || Produces high levels of lactic acid for kettle souring and sour mash beers. Suggested for use in wort under 1-2 IBUs. Fermentation Temperature: 90-100F.|-| [[Craft Cultures]] || CCYL510 || L. ''Lactobacillus delbrueckii '' || Homofermentative || || Lactic acid bacteria producing moderate acidity and sour flavors found in Lambics, Berliner Weiss, and Sour Ales. Commercial pitches only.

| [[Craft Cultures]] || CCYL512 || L. ''Levilactobacillus brevis '' || Heterofermentative || || Typically produces more lactic acid than Lactobacillus delbrueckii. Commercial pitches only.

| [[East Coast Yeast]] || ECY32 || ''L. Levilactobacillus brevis'' || Heterofermentative || || Originally isolated from kefir. Bright acidity and hop-tolerant (up to 30 IBU). Fermentation temperature 60 - 80F <ref name="ecy_website">[http://www.eastcoastyeast.com/wild-stuff.html "Wild Yeast / Brettanomyces / Lactic Bacteria". East Coast Yeast website. Retrieved 04/27/2018.]</ref>.

| [[Escarpment Laboratories]] || Lactobacillus Blend || L. ''Levilactobacillus brevis '' and L. ''Lactiplantibacillus plantarum '' || Heterofermentative/Faculatative Heterofermentative || || This blend is designed to be usable at a wide range of temperatures, and is especially suited for kettle souring/sour wortingWort Souring. We recommend pre-acidifying wort to 4.5 with lactic acid, then pitching the Lactobacillus blend in a CO2-purged kettle or fermentor at 32-42°C.

| [[Escarpment Laboratories]] || Lactobacillus brevis Blend 2.0 || L. brevis ''Lacticaseibacillus rhamnosus'' and ''Lactiplantibacillus plantarum'' || Heterofermentative/Faculatative Heterofermentative || || This strain blend is moderately hop-tolerant, and as such it can also be used for long-term souring a product of <10IBU beersour ongoing research into optimizing Lactobacillus strain selection. It also performs well in kettle souring/sour worting where fast and clean lactic acidity is desireda blend of our main L. We recommend pre-acidifying wort to 4.5 plantarum strain with lactic acid, then pitching the a strain of Lactobacillus rhamnosus. This blend has a wide temperature range ( 30ºC to 45ºC) and enhances fruit flavours in a CO2-purged the finished beer, with tasters noting red fruit and guava aromas. It is intended for kettle or fermentor at 35-45°C/quick souring but can also be used in 0 IBU wort.

| [[Fermmentos LabsEscarpment Laboratories]] (Brazil) || FB7 Pure Sour Lactobacillus Secondary Souring Blend || L. plantarum ''Levilactobacillus brevis'' and L. brevis ''Lacticaseibacillus paracasei'' || Heterofermentative/Faculatative Heterofermentative || || Designed for kettle souring. Optimal temperatures This blend of 20-25°C <ref name="fermmentos_catalog_2017">[https://fermmentolabs2 hop resistant Lactobacillus strains (''L.combrevis'' and ''L.br/wpparacasei'') is intended for use in long-content/uploads/2017/07/Cat%C3%A1logo_Fermmento_Labs_TWTF.pdf Fermmentos Labs Catalog. Retrieved 12/21/2017term souring.]</ref>We recommend 15 IBU or less in the first generation.

| [[Fermmentos LabsEscarpment Laboratories]] (Brazil) || FB12 Lactos Lactobacillus Brevis || L. delbruekii and L. rhamnosus ''Levilactobacillus brevis'' || Homofermentative Heterofermentative || || Designed This strain is moderately hop-tolerant, and as such it can also be used for long-term souring of <10IBU beers. It also performs well in kettle souring/wort souring where fast and clean lactic acidity is desired. We recommend pre-acidifying wort to 4. Optimal temperatures of 255 with lactic acid, then pitching the Lactobacillus blend in a CO2-purged kettle or fermentor at 35-30°C <ref name="fermmentos_catalog_2017" />45°C.

| [[Inland Island Brewing & ConsultingEscarpment Laboratories]] || Lactobacillus Delbrueckii|| ''Lactobacillus Delbrueckii'' || Homofermentative || || A single strain of ''L. delbrueckii'' often used for quick souring.|-| [[Escarpment Laboratories]] || Lactobacillus Plantarum || ''Lactiplantibacillus plantarum'' || Facultatively heterofermentative || || A single strain of L. plantarum that performs well in kettle souring/sour worting where fast and clean lactic acidity is desired.|-|Inland Island Yeast [[Escarpment Laboratories]] || INISBCThe Kveik Ring: Lactobacillus paracasei || ''Lacticaseibacillus paracasei'' || Facultatively heterofermentative || || Isolated from [https://www.garshol.priv.no/download/farmhouse/kveik.html#kv5 Terje Raftevold's Hornindal Kveik]. Works well in kettle/quick souring. Temp: 30-40ºC // Acid Profile: Light to moderate (final pH 3.4-3.6) // If co-991 pitching with yeast, give the Lacto a 24 hour head start. Potentially a one time offer for May 2021 <ref>[https://www.facebook.com/escarpmentlabs/posts/4007824289310386:0 Escarpment Labs Facebook Page. Retrieved 05/06/2021.]</ref>.|-|Fermentis | L| SafSour™ LP 652 || ''Lactiplantibacillus plantarum'' || Faculatative Heterofermentative || No starter recommended for dried format || An optimum dosing rate of 10 g/hL provides a lactic fermentation within 24h – 36h in non-hopped wort <ref>[https://fermentis.com/en/fermentation-solutions/you-create-beer/safsour-lp-652 SafSour™ LP 652. Fermentis website. Retrieved 03/14/2020.]</ref>. See also Fermentis presentation [https://www.youtube.com/watch?v=ThuTjHnnYqk here] for impacts on temperature, starting gravity, aerobic/anaerobic fermentation, and sensory impact of different strains of ''S. cerevisiae'' when kettle souring. |-| Fermentis || SafSour™ LP 1 || ''Levilactobacillus brevis '' || Heterofermentative || No starter recommended for dried format || Produces more An optimum dosing rate of 10 g/hL provides a lactic acid fermentation. It is recommended to pitch directly into the non-hopped wort at higher temperatures the temperature of 32°C (+/- 5°C) <ref>[https://fermentis.com/en/product/safsour-lb-1/ SafSour™ LP 1. Fermentis website. Retrieved 10/20/2021.]</ref>. See also Fermentis presentation [https://www.youtube.com/watch?v=ThuTjHnnYqk here] for impacts on temperature, starting gravity, aerobic/anaerobic fermentation, and in low hop wortssensory impact of different strains of ''S. cerevisiae'' when kettle souring. 70-95 F Temperature Range|- | [[Inland Island Brewing & Consulting|Inland Island Yeast LaboratoriesFermmentos Labs]] (Brazil - CLOSED) || INISBC-992 FB7 Pure Sour || ''Lactiplantibacillus plantarum'' and ''L. delbruekii brevis'' || Homofermentative Facultatively heterofermentative /Heterofermentative || || Produces more lactic acid at higher Designed for kettle souring. Optimal temperatures and in low hop wortsof 20-25°C <ref name="fermmentos_catalog_2017">[https://fermmentolabs.com.br/wp-content/uploads/2017/07/Cat%C3%A1logo_Fermmento_Labs_TWTF.pdf Fermmentos Labs Catalog. 70-95 F Temperature RangeRetrieved 12/21/2017.]</ref>.

| [[Inland Island Brewing & Consulting|Inland Island Yeast LaboratoriesFermmentos Labs]] (Brazil - CLOSED) || INISBC-932 FB12 Lactos || L. fermentum ''Lactobacillus delbruekii'' and ''Lacticaseibacillus rhamnosus'' || Heterofermentative Homofermentative || || Designed for kettle souring. Optimal temperatures of 25-30°C <ref name="fermmentos_catalog_2017" />.

| [[GigaYeast]] (CLOSED) || GB110 || L. ''Lactobacillus delbrueckii''? <ref>[https://www.facebook.com/GigaYeast/posts/565914926872849?comment_id=567669393364069&offset=0&total_comments=1&notif_t=feed_comment From Gigayeast, Inc. on Facebook, 12/3/2014: "Appears to be L. delbrueckii."]</ref> || Heterofermentative || For a 5 gallon batch of beer use 2 liters at 1.040 with high quality yeast nutrient. Keep as close to 86°F (30°C) as possible for 3-4 days with frequent rousing (no stir plate) <ref>Personal Communication with Jim Thompson.</ref>. || Lactic Acid Bacteria are inhibited by hops, high gravity and low temperatures. You can adjust sourness by increasing or decreasing these variables. More than 7 IBU, gravity above 1050 or temps below 65 F will increase the time to sour or lead to reduced overall souring. Contains ~200 billion cells per homebrew pitch <ref name="sbb2.0"></ref>.

| [[Inland Island Brewing & Consulting|Inland Island Yeast Laboratories]] || INISBC-991 || ''Levilactobacillus brevis'' || Heterofermentative || || Produces more lactic acid at higher temperatures and in low hop worts. 70-95 F Temperature Range|- | [[Inland Island Brewing & Consulting|Inland Island Yeast Laboratories]] || INISBC-992 || ''Lactobacillus delbruekii'' || Homofermentative || || Produces more lactic acid at higher temperatures and in low hop worts. 70-95 F Temperature Range|-| [[Inland Island Brewing & Consulting|Inland Island Yeast Laboratories]] || INISBC-932 || ''Limosilactobacillus fermentum'' || Heterofermentative || || |-| [[Jasper Yeast]] || JY-LPLANT || ''Lactiplantibacillus plantarum'' || Facultatively heterofermentative || || Ideal for kettle souring. Optimum temperature is 100°F-110°F. L. plantarum is hop sensitive, we advise not to use any hops until souring is satisfactory. <ref name="Jasper_Lacto">[https://jasperyeast.com/bacteria "Available Bacteria". Jasper Yeast Website.]</ref> |-| [[Jasper Yeast]] || JY-LBREV || ''Levilactobacillus brevis'' || heterofermentative || || Ideal for kettle souring. works well at 95°F-105°F. <ref name="Jasper_Lacto"/> |-| [[Jasper Yeast]] || Lactobacillus blend || ''Lactiplantibacillus plantarum'' and ''Levilactobacillus brevis'' || Facultatively heterofermentative/heterofermentative || || Ideal for kettle souring. Optimum temperature is 95°F-110°F. L. plantarum is hop sensitive, we advise not to use any hops until souring is satisfactory. <ref name="Jasper_Lacto"/>|-| [[Jasper Yeast]] || JY-LACID || ''Lactiplantibacillus acidophilus''|| Homofermentative || || Optimum temperature is 95°F-105°F. <ref name="Jasper_Lacto"/>|-| Lallemand || WildBrew Sour Pitch || L. ''Lactiplantibacillus plantarum '' <ref>[https://www.facebook.com/Lallemandyeasts/photos/a.941604692537326.1073741829.939455986085530/1656901501007638/?type=3&comment_id=1657229347641520&reply_comment_id=1657231934307928&comment_tracking=%7B%22tn%22%3A%22R5%22%7D Post on the Lallemand Facebook page. 09/22/2017. Retrieved 09/22/2017.]</ref> || Facultatively heterofermentative || || See [https://www.facebook.com/groups/MilkTheFunk/permalink/1790290834332456/ this information from Scott Lucas on MTF]. This culture comes in a dry (desiccated) format. Although the [http://www.lallemandbrewing.com/product-details/wildbrew-sour-pitch manufacturer's website] claims this strain is tolerant of 4 IBU, we recommend that brewers treat this strain like any other strain of ''L. plantarum'' and do not expose it to any hops until the desired acidity has been produced (for example, see [[Wort Souring]]). Recommended temperature: 95-100°F (35-38°C) <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1882643148430557/?comment_id=1883360638358808&reply_comment_id=2017197581641779&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Caroline Smith (rep from Lallemand). Milk The Funk Facebook group regarding Lallemand WildBrew Sour Pitch. 03/09/2018.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1988756664485871/?comment_id=1990170714344466&reply_comment_id=2017220451639492&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Caroline Smith (rep from Lallemond). Milk The Funk Facebook group regarding Lallemand WildBrew Sour Pitch and IBU tolerance. 03/09/2018.]</ref>.

Reports in MTF on hop tolerance are mixed: Thomas Delaney reported no souring with 4 IBU, while Warren Knowles reported slower souring to 3.2 in 48 hours with ~5 IBU. Adam Stout reported a pH drop from 5.4 to 5.0 over 24 hours with ~3-5 IBU. Knowles, Matt Lange, and Matt Waugh reported light THP for a few days that went away or dimished by serving time but otherwise clean acidity and good results <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1988756664485871/ Various Milk The Funk members. MTF post on the Lallemand WildBrew Sour Pitch product. 02/14/2018.]</ref>.  The homebrew pitch is enough for two 5 gallon/19 liter batches, but the package is not vacuum-sealable. It is recommended to seal the original sachet without vacuum sealing, and then double bag it into a bvacuum-sealable package and store in the freezer. This will help prevent contamination (see reference for anecdotes of saving left-over open packages of this product) <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/3204419266252932/?comment_id=3205432392818286 Gianmaria Ricciardi, Lallemand Brewing sales representative. Milk The Funk thread on saving Lallemand Wild Brew opened packages. 01/14/2020.]</ref>. |-| Lallemand || WildBrew Helveticus || ''Lactobacillus helveticus'' || Homofermentative || || Temp range: 38°C - 45°C (100°F - 113°F). Hop tolerance: In lab tests, growth was inhibited at 4ppm iso-alpha acid, but they recommend no hops during kettle souring. The pH range is 3.0-3.5 (within 36 hours). Dosage: 10g/hL <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/3016721145022746/?comment_id=3016866791674848&reply_comment_id=3017521094942751 Joan Montasell from Lallemand Brewing. Milk The Funk Facebook thread on Lallemand WildBrew Helveticus. 11/01/2019.]</ref>. [https://www.facebook.com/groups/MilkTheFunk/permalink/3016721145022746/ MTF thread on availability and personal experiences using it.]|-| [[Mainiacal Yeast]] (CLOSED) || MYLP1 || ''Lactiplantibacillus plantarum'' || Facultatively heterofermentative || || Isolated from flowers at King Richards Faire in Massachusetts. It produces a clean lactic sour and prefers it a little cooler however does sour more quickly at its higher temps. Recommended fermentation temperature is 70-90°F <ref name="Amaral_Mainiacal">Private correspondence with Justin Amaral by Dan Pixley. 01/24/2018.]</ref>. '''Commercial pitches only'''.|-| [[Mainiacal Yeast]] (CLOSED) || MYLP2 || ''Lactiplantibacillus plantarum'' || Facultatively heterofermentative || || Isolated from grains going through the steeping process at Blue ox Malthouse. It produces a clean lactic sour and is a viable option for kettle souring, co-pitching, or post fermentation. Recommended fermentation temperature is 70-105°F <ref name="Amaral_Mainiacal" />. '''Commercial pitches only'''.

| [[Mainiacal Yeast]] (CLOSED) || MYLP1 MYLD1 || L. plantarum ''Lactobacillus delbruekii'' || Facultatively heterofermentative Homofermentative || || Isolated from flowers at King Richards Faire in Massachusettsa spontaneous beer, this strain likes it warm but not to hot. It does not sour as quickly and will require some longer aging times to reach terminal pH. It produces a clean lactic sour and prefers it acidity with a little cooler however does sour more quickly at its higher tempshint of farmhouse like straw. Recommended fermentation temperature is 7065-90°F <ref name="Amaral_Mainiacal">Private correspondence with Justin Amaral by Dan Pixley. 01/24/2018.]</ref>. '''Commercial pitches only'''.

| [[Mainiacal Yeast]] (CLOSED) || MYLP2 MYLB2 || L. plantarum ''Levilactobacillus brevis'' || Facultatively heterofermentative Heterofermentative || || Isolated from grains going through the steeping process at Blue ox Malthouse. It produces Produces a clean lactic sour acidity, but generally doesn't produce as much lactic acid as some other variants. It's best used co-pitched with other microbes and is allowed to age. Expect this strain to be a viable option for kettle bit lighter on the souring, co-pitching, or post fermentationside leaving a tart refreshing beer. Recommended fermentation temperature is 7060-105°F 85°F <ref name="Amaral_Mainiacal" />. '''Commercial pitches only'''.

| [[Mainiacal Omega YeastLabs]] || MYLD1 OYL-605 || L. delbruekii ''Levilactobacillus brevis'', <span style="text-decoration: line-through;">''delbrueckii''</span>, and ''plantarum'' blend || Homofermentative Hetero/Hetero <ref name="mtf_wiki_shaner"></ref> || 1 liter starter for a 5 gallon batch of beer at room temperature for 24-48 hours. No stir plate unless kept anaerobic. || Isolated from a spontaneous beer, this strain likes it warm but Quick souring. Pitch into 65°F-95°F <ref name="adi_oyl605"></ref>. Holding temperature is not to hotrequired. It does not sour as quickly and will require some No longer aging times to reach terminal pHcontains delbruekii <ref>[https://www.facebook. It produces a clean acidity com/groups/MilkTheFunk/permalink/1065268213501392/?comment_id=1065669443461269&offset=0&total_comments=18&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with a hint Raymond Wagner of farmhouse like strawOso Brewing Co on Milk The Funk. Recommended fermentation temperature 4/30/2015.]</ref>. Don't use any hops if possible. 2 IBU is 65a good target if hops must be used <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1092523807442499/?comment_id=1092571350771078&offset=0&total_comments=6&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Conversation with Lance Shaner on MTF in regards to IBU tolerance of OYL-90°F 605. 6/15/2015.]</ref>. Contains ~150 billion cells per homebrew pitch <ref name="Amaral_Mainiacalsbb2.0" >[http://sourbeerblog.com/lactobacillus-2-0-advanced-techniques-for-fast-souring-beer/ Lactobacillus 2.0 – Advanced Techniques for Fast Souring Beer. Sour Beer Blog. Matt Miller. 11/18/2015. Retrieved 11/19/2015.]</ref>. This product is vegan <ref>Adi Hastings. Private correspondance with Dan Pixley. '''Commercial pitches only'''08/17/2018.</ref>.

| [[Mainiacal YeastPropagate Lab]] || MYLB2 MIP-911 || L. ''Levilactobacillus brevis '' || Heterofermentative || || Produces a clean lactic acidity, but generally doesn't produce as much lactic acid as some other variantsAcidifies unhopped wort in 48 hours at 100°F <ref>[http://www.propagatelab. It's best used cocom/mip911-pitched with other microbes and allowed to agelactobrevis Propagate Lab. Expect this strain to be a bit lighter on the souring side leaving a tart refreshing beer MIP-911. Recommended fermentation temperature is 60-85°F Retrieved 06/20/2020.]</ref name="Amaral_Mainiacal" />. '''Commercial pitches only'''.

| [[Omega Yeast LabsPropagate Lab]] || OYLMIP-605 912 || L. brevis, <span style="text-decoration: line-through;">delbrueckii</span>, and plantarum blend ''Lactobacillus delbruekii'' || Hetero/Hetero <ref name="mtf_wiki_shaner"></ref> Homofermentative || 1 liter starter for a 5 gallon batch of beer at room temperature for 24-48 hours. No stir plate unless kept anaerobic. || Quick souring. Pitch into 65°F-95°F <ref name="adi_oyl605"></ref>. Holding temperature is not required. No longer contains delbruekii <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1065268213501392/?comment_id=1065669443461269&offset=0&total_comments=18&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Raymond Wagner Acidifies over an extended period of Oso Brewing Co on Milk The Funk. 4/30/2015.]</ref>. Don't use any hops if possible. 2 IBU is a good target if hops must be time; used in barrel aging <ref>[httpshttp://www.facebookpropagatelab.com/groups/MilkTheFunk/permalink/1092523807442499/?comment_id=1092571350771078&offset=0&total_comments=6&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Conversation with Lance Shaner on MTF in regards to IBU tolerance of OYLmip912-605lactodelbureckii Propagate Lab. 6/15/2015.]</ref>. Contains ~150 billion cells per homebrew pitch <ref name="sbb2.0">[http://sourbeerblog.com/lactobacillus-2-0-advanced-techniques-for-fast-souringMIP-beer/ Lactobacillus 2.0 – Advanced Techniques for Fast Souring Beer. Sour Beer Blog. Matt Miller. 11/18/2015912. Retrieved 1106/1920/20152020.]</ref>.

| [[RVA Yeast LabsPropagate Lab]] || RVA 600 MIP-913 || L. rhamnosus GG ''Lacticaseibacillus casei'' || Homofermentative Facultative Heterofermentative || No starter necessary per RVA || Homofermentative Lacto strain found in probiotics; sensitive to hops; does well at room temperature.

| [[SouthYeast LabsPropagate Lab]] || Lactobacillus 1 MIP-914 || Unknown ''Lactiplantibacillus plantarum'' || Facultative Heterofermentative || || SourceAcidifies unhopped wort in 48 hours at 100°F <ref>[http: Spontaneously infected beer (South Carolina)//www.propagatelab.com/mip-914lactoplantarum Propagate Lab. Best suits Light sours, gose, farmhouse saison (mediumMIP-914. Retrieved 06/20/2020.]</high acidity)ref>.

| [[SouthYeast RVA Yeast Labs]] || Lactobacillus 2 RVA 600 || Unknown ''Lacticaseibacillus rhamnosus'' || Homofermentatative Homofermentative || No starter necessary per RVA || Source: Prickly pear fruit (South Carolina)Homofermentative Lacto strain found in probiotics; sensitive to hops; does well at room temperature. Best suits strong sours, and lambic (high acidity).

| [[The Yeast BaySouthYeast Labs]] (CLOSED) || Lactobacillus Blend 1 || L. plantarum, L. brevis, and an unidentified ''Lactobacillus'' species Unknown || Heterofermentative || || The Lactobacillus Blend includes three strainsSource: Lactobacillus plantarum, Lactobacillus brevis and a strain of Lactobacillus isolated from a very unique brewer of American sour beers the returned a sequencing result of "uncultured Lactobacillus". Sure to please anyone with a knack for creating sour beers, it can quickly produce acidity across a wide range of temperatures. This blend can be used on its own for kettle souring prior to pitching yeast to create acidity quickly, or co-pitched with yeast to create sourness over time. It will produce a pronounced and rounded acidity that is the foundation of any complex sour Spontaneously infected beer. We recommend holding the IBU on the low end (< 2-3) if you'd like to use this blend to create acidity in a shorter time frame. Higher IBUs may result in very slow or no souring (testing is still ongoing to determine IBU at which lactic acid production is inhibited). Temperature: 70-90°F. Cell count: 50-80 million cells/mL (1.75-2.8 billion cells for 35 mL homebrew vialsSouth Carolina) <ref name="WL_cellcounts"></ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1280135442014667/?comment_id=1280341068660771&reply_comment_id=1280498695311675&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Conversation with Nick Impellitteri on MTF regarding TYB Lactobacillus Blend cell counts. 04/08/2016.]</ref>. Recommended temperature range for fastest acid production for kettle souring is 85-90°FBest suits Light sours, although if kept in the 70's it should produce good acidification in 48-72 hours. A major drop off of in acid production is seen above 90°F <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1616265398401668/?comment_id=1617001948328013&comment_tracking=%7B%22tn%22%3A%22R%22%7D Impellitterigose, Nick. Milk The Funk Facebook group. 03farmhouse saison (medium/17/2017.]</ref>high acidity).

| [[The Yeast BaySouthYeast Labs]] (CLOSED) || TYB282 Lactobacillus 2 || L. brevis Unknown || Heterofermentative Homofermentatative || || TYB282 is a single strain of Lactobacillus brevis isolated out of an unintentionally soured golden ale produced by a Mexican craft brewery.This strain produces a nice, clean lactic acidity Source: Prickly pear fruit (down to ~pH 3.16-3.18South Carolina) in unhopped wort within 36 hours at a temperature of ~72-77 F. The higher the temperature (up to 90 F is what we've tested), the faster the acid production. This is a great strain for kettle souring Best suits strong sours, as it grows rather quickly and produces lambic (high acidity fast with no detectable off flavors. We are about to begin some trials in hopped wort to test out the acidification in the presence of hop compounds, though we presume there is some level of adaptation to hop compounds given the environment in the beer from which we cultured the strain. Temperature: 70-90 ºF).

| [[White LabsThe Yeast Bay]] || WLP677 Lactobacillus Blend || L. delbrueckii (might be misidentified <ref>[http://masterbrewerspodcast.com/085-lactic-acid-bacteria-case-study Tim Lozen. Master Brewers Association podcast interview on lactic acid bacteria case study. 04/23/2018.]</ref>) ''Lactiplantibacillus plantarum'', and 2 strains of ''Levilactobacillus brevis'' || Heterofermentative <ref name="mtf_wiki_shaner">[http://www.milkthefunk.com/wiki/100%25_Lactobacillus_Fermentation Milk || || The Funk Wiki. 100% Lactobacillus Fermentation Test by Lance Shaner.]</ref><ref name="tmf_cultures">[httpBlend includes three strains://www.themadfermentationist.com/p/commercial-cultures.html ''Commercial BrettanomycesLactobacillus plantarum'', ''Lactobacillus, brevis'' and Pediococcus Descriptionsa second strain of ''Lactobacillus brevis'' isolated from an accidentally soured blonde ale from a Mexican craft brewery. The Mad Fermentationist BlogQuickly produces acidity across a wide range of temperatures. It can be used on its own for kettle souring prior to pitching yeast to create acidity quickly, or co-pitched with yeast to create sourness over time. Michael TonsmeireIt will produce a pronounced and rounded acidity. Retrieved The Yeast Bay recommends holding the IBU on the low end (< 2-3/4/2015) if you'd like to use this blend to create acidity in a shorter time frame.]</ref> || no stir plateHigher IBUs may result in souring, room temp ||Incubate at > but the strain of ''L. brevis'' isolated from the Mexican craft brewery is hop tolerant up to about 15-20 IBU. Temperature: 70-90°F and < 117°F for 5-7 days for greater lactic acid production. Cell count: 50-80 million cells/mL (1.75-2.8 billion cells in a for 35 mL homebrew vialvials) <ref name="WL_cellcounts">Private correspondence with White Labs Customer Service and Dan Pixley. 10/29/2015.</ref>. Not a good strain for kettle souring, but can produce a "soft" acidity over a longer period of time <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/12124551921160261280135442014667/?comment_id=12124758887806231280341068660771&reply_comment_id=12124765754472211280498695311675&comment_tracking=%7B%22tn%22%3A%22R322R1%22%7D Conversation with Andrew Addkison Nick Impellitteri on MTFregarding TYB Lactobacillus Blend cell counts. 0104/1208/2016.]</ref>. White Labs claims that it Recommended temperature range for fastest acid production for kettle souring is tolerant to up to 20 IBU85-90°F, although growth starts to become inhibited at 15 IBU <ref name="WL_datasheet" /><ref>[http://www.themadfermentationist.com/p/commercialif kept in the 70's it should produce good acidification in 48-cultures72 hours.html "Commercial Brettanomyces, Lactobacillus, and Pediococcus Descriptions; Commercial Yeast Laboratories." The Mad Fermentationist blog. Michael Tonsmeire. Retrieved 12/12/2016.]</ref>. Generally heat tolerant, but sours faster between 100-110°F A major drop off of in acid production is seen above 90°F <ref name="WL_datasheet">[httphttps://www.whitelabsfacebook.com/sitesgroups/defaultMilkTheFunk/filespermalink/R1616265398401668/?comment_id=1617001948328013&comment_tracking=%26D7B%20Wild22tn%20Yeast22%20and3A%20Bacteria22R%20Experiments_2.pdf "R&D Wild Yeast and Bacteria Experiments"22%7D Impellitteri, Nick. White Labs data sheetMilk The Funk Facebook group. Retrieved 0503/1617/2017.]</ref>.

| [[White LabsThe Yeast Bay]] || WLP672 TYB282 || L. ''Lactiplantibacillus brevis '' || Heterofermentative <ref name="mtf_wiki_shaner"></ref><ref name="nick">[https://www.facebook.com/groups/MilkTheFunk/permalink/1029638267064387/?comment_id=1030638553631025&offset=0&total_comments=24 Conversation with Nick Impellitteri from The Yeast Bay on the MTF Facebook Group. 3/4/2015.]</ref> || No stir plate, room temp|| Produced TYB282 is a single strain of Lactobacillus brevis isolated out of an unintentionally soured golden ale produced by [[a Mexican craft brewery.This strain produces a clean lactic acidity (down to ~pH 3.16-3.18) in unhopped wort within 36 hours at a temperature of ~72-77 F. The Yeast Bay]]higher the temperature (up to 90 F is what we've tested), the faster the acid production. More hop tolerant than other Lacto strainsRecommended for kettle souring, however TYB advises to use wort as it grows rather quickly and produces acidity fast with less than 10 IBUno detectable off flavors. White Labs data sheet shows that growth is inhibited to 82% The Yeast Bay has tested this strain at 5 ~20 IBU, and 60% it was able to reduce the pH of beers down to 3.30 pH when co-pitched with a farmhouse yeast. It might create acidity at 10 higher IBU <ref name="WL_datasheet" />. Temperature range: 70-95°F 's (greatly inhibited at 110°FNick suggests maybe up to 30 IBU) <ref name="WL_datasheet" />; 80% attenuation (however, this may has not reflect actual attenuation of wort in a real brewery; see reference been tested yet <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/10311154302500042907190232642505/?comment_id=1031244193570461&offset=0&total_comments=33 Conversation with Michael Soo and 2907235245971337 Nick Impellitteri on the . Milk The Funk Facebook GroupFcaebook group post on TYB282 hop tolerance. 309/512/20152019.]</ref>). <ref>[httpTemperature://www.theyeastbay.com/wild-yeast-and-bacteria-products/wlp672-lactobacillus-brevis The Yeast Bay website. Retrieved 3/2/2015.]</ref> Cell count: 5070-80 million cells/mL (1.75-2.8 billion cells for 35 mL homebrew vials) <ref name="WL_cellcounts"></ref>90 ºF.

| [[WyeastWhite Labs]] || 5335 WLP677 || L''Lactobacillus delbrueckii'' (might be misidentified <ref>[http://masterbrewerspodcast.com/085-lactic-acid-bacteria-case-study Tim Lozen. Master Brewers Association podcast interview on lactic acid bacteria case study. buchneri 04/23/2018.]</ref>) || Heterofermentative <ref name="mtf_wiki_shaner">[http://www.milkthefunk.com/wiki/100%25_Lactobacillus_Fermentation Milk The Funk Wiki. 100% Lactobacillus Fermentation Test by Lance Shaner.]</ref><ref name="tmf_cultures">[http://www.themadfermentationist.com/p/commercial-cultures.html ''Commercial Brettanomyces, Lactobacillus, and Pediococcus Descriptions''. The Mad Fermentationist Blog. Michael Tonsmeire. Retrieved 3/4/2015.]</ref> || 1 liter starter for a 5 gallon batch of beer, 1.020 DME sterile wort, no stir plate, no O2, starter at 90°F if possible 5-7 days room temp || Incubate at > 90°F and < 117°F for 5-7 days for greater lactic acid production. Cell count: 1.0 x 10⁸ (100 50-80 million) cells/mL (10 1.75-2.8 billion cells in a 100 35 mL homebrew pouchvial) <ref name="wyeast_cellcountsWL_cellcounts">Private correspondence with White Labs Customer Service and Dan Pixley. 10/29/2015.</ref>. Not a good strain for kettle souring, but can produce a "soft"acidity over a longer period of time <ref>[https://drivewww.googlefacebook.com/folderviewgroups/MilkTheFunk/permalink/1212455192116026/?idcomment_id=0B8CshC9nxYHdZmE4MmoyLXA2WVk1212475888780623&uspreply_comment_id=sharing Wyeast Specifications 2015 Retail Products1212476575447221&comment_tracking=%7B%22tn%22%3A%22R3%22%7D Conversation with Andrew Addkison on MTF. 01/12/2016.]</ref>. White Labs claims that it is tolerant to up to 20 IBU, although growth starts to become inhibited at 15 IBU <ref name="WL_datasheet" /><ref>[http://www.themadfermentationist.com/p/commercial-cultures.html "Commercial Brettanomyces, Lactobacillus, and Pediococcus Descriptions; Commercial Yeast Laboratories." The Mad Fermentationist blog. Michael Tonsmeire. 2015 Retrieved 12/12/2016.]</ref>. Generally heat tolerant, but sours faster between 100-110°F <ref name="WL_datasheet">[http://www.whitelabs.com/sites/default/files/R%26D%20Wild%20Yeast%20and%20Bacteria%20Experiments_2.pdf "R&D Wild Yeast and Bacteria Experiments". White Labs data sheet. Retrieved 05/16/2017.]</ref>

| [[White Labs]] || WLP672 || ''Levilactobacillus brevis'' || Heterofermentative <ref name="mtf_wiki_shaner"></ref><ref name="nick">[https://www.facebook.com/groups/MilkTheFunk/permalink/1029638267064387/?comment_id=1030638553631025&offset=0&total_comments=24 Conversation with Nick Impellitteri from The Yeast Bay on the MTF Facebook Group. 3/4/2015.]</ref> || No stir plate, room temp|| Produced by [[The Yeast Bay]]. More hop tolerant than other Lacto strains, however TYB advises to use wort with less than 10 IBU. White Labs data sheet shows that growth is inhibited to 82% at 5 IBU, and 60% at 10 IBU <ref name="WL_datasheet" />. Temperature range: 70-95°F (greatly inhibited at 110°F) <ref name="WL_datasheet" />. <ref>[http://www.theyeastbay.com/wild-yeast-and-bacteria-products/wlp672-lactobacillus-brevis The Yeast Bay website. Retrieved 3/2/2015.]</ref> Cell count: 50-80 million cells/mL (1.75-2.8 billion cells for 35 mL homebrew vials) <ref name="WL_cellcounts"></ref>. This strain can take several days to acidify unhopped wort, and as such is not recommended by MTF for kettle sours. This strain benefits from magnesium nutrient additions, and is slightly inhibited by zinc nutrient additions <ref>[https://www.mdpi.com/2218-273X/10/12/1599 Chemical Composition of Sour Beer Resulting from Supplementation the Fermentation Medium with Magnesium and Zinc Ions. Aneta Ciosek, Katarzyna Fulara, Olga Hrabia, Paweł Satora, and Aleksander Poreda. 2020. DOI: https://doi.org/10.3390/biom10121599.]</ref>.|-| [[Wyeast]] || 5335 || ''Lentilactobacillus buchneri'' || Heterofermentative <ref name="mtf_wiki_shaner"></ref> || 1 liter starter for a 5 gallon batch of beer, 1.020 DME sterile wort, no stir plate, no O2, starter at 90°F if possible 5-7 days || Incubate at 90°F for 5-7 days for greater lactic acid production. Cell count: 1.0 x 10⁸ (100 million) cells/mL (10 billion cells in a 100 mL homebrew pouch) <ref name="wyeast_cellcounts">[https://drive.google.com/folderview?id=0B8CshC9nxYHdZmE4MmoyLXA2WVk&usp=sharing Wyeast Specifications 2015 Retail Products. 2015.]</ref>. |-| [[Wyeast]] || 5223-PC || L. ''Levilactobacillus brevis '' || Heterofermentative <ref name="mtf_wiki_shaner"></ref><ref name="nick"></ref> || no stir plate, room temp is fine || Heterofermentative (produces lactic acid, ethanol and CO2), more hop tolerant. Does well at room temperature. AVAILABLE ONLY FROM JULY THROUGH SEPTEMBER 2014 (Michael Dawson from Wyeast indicated that this culture may return at some point). Jamie Daly indicated on MTF that he got almost no sourness after 24 hours at 100°F (37.8°C). He lowered the temperature to 90°F-95°F (32.2°C-35°C) for 36 hours, and the pH of the wort went down to 3.29. Thus, Jamie recommends 90°F-95°F (32.2°C-35°C) for 60 hours for better souring; avoid warmer temperatures. He also aerated his starter of L. brevis (2L starter of 1.020 DME) and set it on a stir plate at 95°F <ref name="brevis_aeration">[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC547135/ Growth Response of Lactobacillus brevis to Aeration and Organic Catalysts. J. R. Stamer and B. O. Stoyla. Appl Microbiol. Sep 1967; 15(5): 1025–1030.]</ref>. The beer wort was not aerated, and the fermenter was flushed with CO2. These methods need verification. Cell count: 1.0 x 10⁸ (100 million) cells/mL (10 billion cells in a 100 mL homebrew pouch) <ref name="wyeast_cellcounts"></ref>.|-| [[Wyeast]] || 4335 || ''Lactobcillus delbruekii'' || Heterofermentative || || There are [https://www.google.com/search?safe=off&rlz=1C1CHBF_enUS741US743&ei=BAuPW-WyL8OAk-4PuoGryA8&q=wyeast+4335&oq=wyeast+4335&gs_l=psy-ab.3..0i30.16026.16026..16511...0.0..0.83.83.1......0....1..gws-wiz.......0i71.9JdIoR14NT8 various references on the internet during the mid to late 2000's] to a product called "Wyeast 4335 ''Lactobacillus delbruekii''", however, this product is no longer offered by Wyeast. When asked about this product, the Wyeast customer support reported that the "4335" product was renamed to "5335" fifteen years ago, and the "5335" and "4335" products are the same culture. It is unclear why "4335" was labeled as ''L. delbruekii'', but it is likely that it was originally misidentified <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2265479906813544/?comment_id=2267884689906399&comment_tracking=%7B%22tn%22%3A%22R%22%7D Chris Cates private correspondance with Wyeast customer service representative. Milk The Funk Facebook thread on the origin and disappearance of WY4335 ''L. delbruekii''. 09/04/2018.]</ref>.

The recipe for this starter wort is: '''1.040 SG (10°P) Dried Malt Extract wort with 10% apple juice + 20 1.5-2 grams of chalk (CaCO3) per liter + yeast nutrients'''(originally, Aeschlimann recommended 20 grams of chalk, but we now recommend a much smaller amount of chalk; see below for details). This starter wort might be as effective without the 10% apple juice addition, but this has not been tested as far as we know. Regarding the use of chalk, it is the preferred buffer because it does not react is relatively nonreactive with CO2 (unlike CO₂ compared to something like baking soda), so it won't be consumed by exposure to air or due to CO2 CO₂ production by the Lacto''Lactobacillus''. It also has a pKa (maximum buffering capacity) of around 4.6, which is ideal for ''Lactobacillus'' growth. The fact that it easily precipitates out also makes it ideal to use as a buffer <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1180630378631841/?comment_id=1181674265194119&reply_comment_id=1181743348520544&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Bryan of Sui Generis Blog regarding the use of chalk as a buffer in Lacto starters. 11/20/2015.]</ref>. Jeff Mello from [[Bootleg Biology]], Nick Impellitteri from [[The Yeast Bay]], and Bryan from [https://suigenerisbrewing.blogspot.com/ Sui Generis blog] suggest that using the smaller amount of 1.5-2 grams of CaCO3 per liter is preferable because that amount is easier to precipitate out of the starter and avoid pitching into the beer (the growth differences from using less chalk has not been tested though) <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1369904163037794/?comment_id=1370329352995275&reply_comment_id=1372184639476413&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Jeff Mello on MTF regarding using less chalk in LAB starters. 08/10/2016.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1619935741367967/?comment_id=1619986154696259&reply_comment_id=1619991214695753&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Impellitteri, Nick. Milk The Funk Facebook group. 03/19/2017.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1457469187614624/?comment_id=1457541770940699&reply_comment_id=1457620514266158&comment_tracking=%7B%22tn%22%3A%22R%22%7D Bryan from Sui Generis. MTF Thread on using 1.5g/L of chalk for Lactobacillus starters. 11/02/2016.]</ref>. To create a 1 liter starter for 20 liters of wort, follow these directions:

# Cool the DME wort to the desired incubation temperature (see step 4), and add 100 mL of pasteurized apple juice, 1.5-2-20 grams of chalk (CaCO3), and half a teaspoon of yeast nutrients. The chalk won't dissolve into solution, so don't worry about it. <ref name="sam_starter">[https://eurekabrewing.wordpress.com/2015/05/18/evaluate-starter-media-to-propagate-lactobacillus-sp/ Evaluate starter media to propagate Lactobacillus sp., Eureka Brewing Blog, by Samuel Aeschlimann.]</ref>. Boiling the apple juice might destroy some of the nutrients in the apple juice that assist ''Lactobacillus'' in its growth, and since it is pasteurized boiling it is not necessary <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1152787381416141/?comment_id=1153930734635139&reply_comment_id=1153949097966636&total_comments=4&comment_tracking=%7B%22tn%22%3A%22R6%22%7D Conversation with Samuel Aeschlimann and Jason Pappas on MTF about the effects of boiling apple juice. 09/24/2015.]</ref>.

# Reference the above [[Lactobacillus#Culture_Charts|Culture Charts]] for how long the starter should be incubated for before pitching(24-48 hours is a general rule of thumb). If a stir plate is not used, one indication that the starter is done will be when the top of the starter begins to clear (turbidity is an indication that the culture is growing, and once the top portion of the starter starts to clear then that is a sign that growth has stopped) <ref name="Sam_starter2">[https://www.facebook.com/groups/MilkTheFunk/permalink/1131778916850321/?comment_id=1131806746847538&offset=0&total_comments=6&comment_tracking=%7B%22tn%22%3A%22R2%22%7D Conversation with Sam Aeschlimann of Eureka Brewing Blog on MTF. 08/20/2015.]</ref>.

======Notes On Safety======It is well documented that many pathogens can grow in wort when the pH is above 4.5 and ethanol is not present or very low. While it may be possible for pathogens to grow in the environment created by adding chalk to the starter, the chances of this are very low. There are a few reasons for this low risk. Firstly, typical brewing sanitation regimes and the use of commercial pure cultures of ''Lactobacillus'' should prevent unwanted microbes from contaminating the starter media. Additional steps can be taken with [[Quality Assurance|quality assurance]] to ensure the purity of the starter. Secondly, once the starter is added to wort and the wort drops below a pH of 4.6, any contaminating microbes will be killed. In the case of [[Wort_Souring#Souring_in_the_Boiler_.28Kettle_Sour.29|kettle souring]], any contaminating pathogens will be killed during the second boiling step. Finally, yeast fermentation will ensure that pathogens are not able to survive once the pH levels drop below 4.6 and ethanol is produced. For example, a similar pattern of pathogenic bacteria being killed by yeast growth and/or lactic acid bacteria growth can be seen in [[Spontaneous_Fermentation#Microbial_Succession_During_Fermentation|spontaneous fermentation]] where enteric bacteria are often inherently present during the early stages of fermentation, but are quickly killed as the pH drops and ethanol levels rise.  Storing the growth media anaerobically with a pH above 4.5 for more than 3-4 days could result in a very small risk of botulism growth. Therefore, if the starter is going to be stored anaerobically for more than a few days, a target pH under 4.6 should be achieved to prevent the growth of botulism or other pathogenic contaminants. Additionally, the starter should be stored cold to further inhibit the growth of most potential contaminating microorganism species. For more information on the general risks of pathogens in beer/wort/starters, see the [[Wild_Yeast_Isolation#Safety|Wild Yeast Isolation Safety wiki page]], the [[Mold|Mold wiki page]], [https://suigenerisbrewing.com/index.php/2017/01/05/fact-of-fiction-can-pathogens-survive-in-beer-the-rdwhahb-edition/ this Sui Generis Blog post], and [https://beerandwinejournal.com/botulism/ this article on the small risk of botulism in wort that is stored for more than a few days by Chris Colby]. ======Modified Versions======* Microbiologist Dr. Matt Humbard uses a modified version of the above recipe: combine 10% apple juice (no preservative) with 1.010 SG wort and a tablespoon of calcium carbonate for every gallon. Grow for 2 days at ~90°F, and then cool to refrigeration temperature and store it cold until ready to use (pitching cold is fine). To maintain the culture long term, every ~4 weeks stir the culture and take 10-15% of the liquid culture and add it to a new batch of starter media, and grow the new starter for 2 days as previously instructed. As long as yeast does not contaminate the process, the lactic acid bacteria can be maintained this way indefinitely <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/3154764734551719/?comment_id=3154792411215618&reply_comment_id=3154838211211038 Dr. Matt Humbard. Milk The Funk Facebook post on maintaining a lactic acid bacteria culture. 12/25/2019.]</ref>.* Nick Impellitteri from [[The Yeast Bay]] shared his formulation for a 1 liter formulation: 25 g Dextrose, 10 g Fermaid O, 2.5 g CaCO3, 100 mL apple juice (no preservatives), 20 mL tomato juice (no preservatives), 1 mL tween 80; QS with DI water to 1L; pH ~6.2-6.3 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/3360639773964213/?comment_id=3360874993940691 Nick Impellitteri. Milk The Funk Facebook group post on his Lactobacillus growth media formulation. 03/20/2020.]</ref>.  See also:* [http://suigenerisbrewing.blogspot.ca/2015/05/lacto-starters.html ''Lacto Starters'', by Bryan of Sui Generis blog] for additional information on ''Lactobacillus'' starters.* For media for growing from stocks, see [[Laboratory_Techniques#Lactobacillus.2FPediococcus|Laboratory Techniques]].

<blockquote>"I typically grow it by itself anaerobically in [http://www.neogen.com/Acumedia/pdf/ProdInfo/7406_PI.pdf MRS media]. Seems to work very well and results in good growth. I've personally had the best success with MRS media (only for growing from frozen stocks; MRS is not food grade and the fermentation byproduct should be decanted or pelleted; MRS should not be used for large scale propagation) and in an anaerobic environment, though I know some ''Lactobacillus'' strains grow aerobically just fine. The problem with growing lactic acid bacteria is the acid they produce will eventually inhibit their own growth. MRS contains a buffer to help combat the drop in pH as a result of LAB metabolism, which keeps the pH around 6-6.5 (I think) for optimal growth. I usually grow them at 35 C, but sometimes incubator space is at a premium (like right now) and I just [use a stir plate with an airlock]" <ref>[https://wwwdrive.facebookgoogle.com/groups/MilkTheFunk/permalink/1031115430250004/open?comment_idid=1031228363572044&offset=0&total_comments=24 1UzqB-Bq4K_4q0rHzYXntJwiIp6XInuWBZLKueYJW8dE Conversation with Nick Impellitteri on Milk The Funk Facebook group. 3/5/2015.]</ref>. - Nick Impellitteri from [[The Yeast Bay]] on general Lactobacillus cell growth </blockquote>

All [https://en.wikipedia.org/wiki/Prokaryote prokaryotes], which includes all bacteria, are categorized based on the levels of oxygen in their environment in which they can grow and how they utilize oxygen if at all <ref name="Todar_nutgro4"></ref>. ''Lactobacillus'' species are usually considered to be "facultative anaerobes" (or "facultative aerobes") <ref name="todar_lactics4"></ref>, however , they are a special case. Facultative anaerobes usually make energy from oxygen if it is present via the [https://en.wikipedia.org/wiki/Oxidative_phosphorylation oxidative phosphorylation pathway], but otherwise engage in anaerobic fermentation <ref>[http://www.ncbi.nlm.nih.gov/books/NBK21208/ Biochemistry. 5th edition. Berg JM, Tymoczko JL, Stryer L. 2002. Chapter 18.]</ref><ref>[http://inst.bact.wisc.edu/inst/index.php?module=book&type=user&func=displayarticle&aid=111 Virtual Microbiology Textbook. Department of Bacteriology, University of Wisconsin-Madison. Retrieved 12/02/2015.]</ref>. ''Lactobacillus'' species can utilize oxygen, but not through the oxidative phosphorylation pathway. They use an alternative pathway instead. This pathway uses flavine-containing oxidases and peroxidases to carry out the oxidation of NADH2 using O2 <ref name="bergey">Bergey's Manual of Systematic Bacteriology, 2nd edition. pg 471</ref><ref>Correspondence with Bryan of Sui Generis Blog from Dan Pixley. 12/01/2015.</ref>. Lactobacilli, therefore, are unique in that they blur the line between facultative anaerobes and another class of prokaryotes known as "aerotolerant anaerobes". Aerotolerant anaerobes do not use oxygen to generate energy but can grow in the presence of oxygen.

The important take away here is that oxygen doesn't significantly affect most ''Lactobacillus'' species. They do not care if oxygen is present in order to grow and produce energy for themselves and lactic acid for brewers. They also do not produce significant amounts of [[Butyric_Acid|butyric acid]] or [[Isovaleric_Acid|isovaleric acid]] in the presence of oxygen <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1182597671768445/?qa_ref=qd&comment_id=1182773928417486&reply_comment_id=11832424050373051183047521723460&comment_tracking=%7B%22tn%22%3A%22R722R9%22%7D Conversation with Dr. Bryan Heit of Sui Generis Blog on MTF regarding butyric acid production by Lactobacillus. 11/23/2015.]</ref>.

There Although it is most likely not relevant to beer brewing applications, there are, however, a few exceptions to this in the scientific literature. For example, ''L. plantarum'', which is a facultatively heterofermentative species, is homolactic without the presence of oxygen and produces only lactic acid. After food sources have been exhausted and in the presence of oxygen, however, ''L. plantarum'' switches to heterolactic fermentation, and further converts lactic acid into acetic acid. In a lab setting the conversion of lactic acid to acetic acid only happened when glucose was no longer available (this may not be the case in wort where other limiting factors such as low pH can prevent ''L. plantarum'' from continuing their metabolic processes before all glucose is consumed, which is the case in kettle souring), and only during the stationary phase (after growth stopped). During the conversion of lactic acid to acetic acid, ''L. plantarum'' also produces hydrogen peroxide (H²0²), which is toxic to microorganisms and is thought to be a protection mechanism for ''L. plantarum'' <ref>[http://www.ncbi.nlm.nih.gov/pubmed/6480562 Physiological role of pyruvate oxidase in the aerobic metabolism of Lactobacillus plantarum. Sedewitz B, Schleifer KH, Götz F.1984.]</ref><ref name="Quatravaux_plantarum"></ref><ref name="microbewiki_plantarum">[https://microbewiki.kenyon.edu/index.php/Lactobacillus_plantarum_and_its_biological_implications Lactobacillus plantarum and its biological implications. Microbe Wiki. Retrieved 6/7/2015.]</ref><ref name="shaner_plantarum"></ref>. This same process has also been observed in one strain of ''L. brevis'' and under similar conditions of depleted nutrients and oxygen <ref>[http://aem.asm.org/content/early/2017/08/21/AEM.01659-17.abstract The oxygen-inducible conversion of lactate to acetate in heterofermentative Lactobacillus brevis ATCC367. Tingting Guo, Li Zhang, Yongping Xin, ZhenShang Xu, Huiying He, and Jian Kong. 2017.]</ref>. It is important to understand that these results were under lab settings and without any sort of brewing application considered in these studies, so they should not be assumed to be important to the brewing process. Omega Yeast Labs reports that no noticeable acetic acid is produced if the oxygen is not purged with their OYL-605 ''Lactobacillus'' blend which contains ''L. plantarum'', and ; brewers should not aerate wort during sour souring but purging O2 is not required <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1222363364458542/?comment_id=1222371257791086&reply_comment_id=1225212894173589&comment_tracking=%7B%22tn%22%3A%22R%22%7D MTF conversation with Adi Hastings from Omega Yeast Labs on the effects of oxygen presence in OYL-605. 02/02/2016.]</ref>. This indicates that acetic acid and hydrogen peroxide production in typical brewing scenarios where little or no oxygen is present is probably not a concern. Oxygenating for yeast is recommended even if the ''Lactobacillus'' is not killed with a second boil, especially if the brewer is relying on one strain of brewers yeast to finish the fermentation. See also [[Mixed_Fermentation#Aeration|Aeration for Mixed Fermentation]]. In some cases, oxygen could benefit some species. For example, one strain of ''L. brevis'' has been shown to increase growth rates in the presence of oxygen <ref name="brevis_aeration"></ref>. Thomas Hübbe's master thesis showed that under lab growth media "VLB-S7-S", "NBB®-A", and MYPG + cyclohexmide, both strains of ''Lactobacillus'' tested (''L. brevis'' and ''L. parabrevis'') did not show growth in an aerobic chamber, but did grow in an anaerobic chamber, although this might be an effect of the growth media and not representative of brewing conditions <ref name="Hubbe">[https://www.facebook.com/groups/MilkTheFunk/permalink/1407620509266159/ Effect of mixed cultures on microbiological development in Berliner Weisse (master thesis). Thomas Hübbe. 2016.]</ref>.

Hops contain multiple compounds which are bacteriostatic. Alpha acids are the best understood, but other compounds such as beta acids, a number of polyphenols (e.g. xanthohumol), and even some of the aromatic oils (e.g. humulene) have been found to have some inhibitory effects on ''lactobacilli''. The later compounds (especially the beta acids) are why aged hops retain inhibitory characteristics, despite being nearly devoid of alpha acids. In all cases these compounds appear to inhibit the bacteria in the same way - all of these compounds contain fairly large, flat-ish, hydrophobic regions. These regions do not "like" to be in water, and thus will be driven into the hydrophobic core of the bacterial plasma membrane. This opens minute holes in the membrane which prevents the bacteria from maintaining ion (in particular, proton) gradients, leading to suppression of growth and even death of the bacteria.

Hop tolerance is not only species dependent, but is also strain dependent. For example, a dissertation by F.J. Methner measured the pH drop of wort that started at a pH of 5.55 from day 3 to day 14 for several strains of ''L. brevis'' at different IBU levels (7,9,11,13 and 18 IBU's). One strain of ''L. brevis'' eventually got down to a pH of 3.8 at day 14 with 7 IBU's, while another strain got down to 3.3 pH at day 14 (with other strains in-between those numbers). At 18 IBU, the relatively hop intolerant ''L. brevis'' strain got down to only 4.2 pH, while another strain got down to 3.7. In general, the higher the IBU, the slower the pH drop. Interestingly, another species called ''L. coryniformis'' was shown to be more hop tolerant than ''L. brevis''. ''L. coryniformis'' dropped the 18 IBU wort down to 3.6 pH over 14 days <ref name="Methner">[https://www.facebook.com/groups/MilkTheFunk/permalink/1537381402956735/ Methner, F.D. Uber Die Aromabildung beim berliner weissebier unter besonderer berucksichtigung von sauren and estern (data reported and translated by Benedikt Rausch Koch on Milk THe Funk Facebook group). 1987.]</ref>.

Methner's data is shown below; graphs created by Benedikt Rausch Koch <ref name="Methner" />. Y axis = pH, X axis = days.

* [[Hops#Antimicrobial_Properties|Hops Antimicrobial Properties]] and [[Hops#Dry_HoppingInhibiting_Lactic_Acid_Bacteria|Dry Hopping Inhibits ''Lactobacillus'']].

* [https:=====Other Plant Type Tolerance=====Other types of plants can also inhibit the growth of ''Lactobacillus''. Nadia Marlen Aasen's Master's Thesis from Norwegian University of Life Sciences reported that ''Juniperus communis'' (common juniper) twigs have a significant impact on the growth of ''Lactobacillus''. The species tested were ''L. plantarum'', ''L. brevis'', and ''L. buchneri''. Individual juniper infusions in water were created using twigs, needles, ripe berries, and unripe berries, and the infusions were measured in grams of plant material per mL of water. Juniper infusions are common in farmhouse brewing, and in Norway they are referred to as ''einerlog''. Juniper twigs infused in water had the most impact on the growth of the species of lactic acid bacteria tested, with ''L. plantarum'' being partially inhibited at around 0.031-1 g//wwwmL. ''L. brevis'' was partially inhibited at 0.ratebeer5-1.com0 g/forums/lab-mL, and''L. buchneri'' was inhibited by 0.125-hops_2890711 g/mL.htm "CLevar" Juniper needles had a very limited impact based on Ratebeerthe concentrations that were tested (up to 1 g/mL).com data point Unripe berries had a very slight impact, and ripe berries did not have a significant impact at all on ''Lactobacillus'' being inhibited by hopsgrowth. No further research was done to determine what the components within juniper twigs are that inhibit LAB or what their concentrations were <ref name="Østlie">[https://nmbu.brage.unit.no/nmbu-xmlui/handle/11250/2681970?show=full Nadia Marlen Aasen. Growth, but not as much by iso-alpha acid hop extractmetabolism and beer brewing with kveik. Master's Thesis. Norwegian University of Life Sciences. 2020.]</ref>.

Peyer et al. (2017) examined the effects of the sugar content of brewer's wort on a strain of ''Lactobacillus amylovorous''. They found that the higher gravity of the wort increased the growth of the ''Lactobacillus'', and therefore also the lactic acid production. This increase was linear until the extract reached 16%Brix (1.065 SG), at which time the growth increase began to slow down. The higher growth and more lactic acid production in higher gravity wort was probably due to increased nutrients as well as a higher buffer capacity. This growth increase plateaued in wort that had was 18-20% sugar contentBrix, which was likely due to osmotic stress on the cells <ref name="Peyer_2017">[http://www.asbcnet.org/publications/journal/vol/2017/Pages/ASBCJ-2017-3861-01.aspx Sour Brewing: Impact of Lactobacillus amylovorus FST2.11 on Technological and Quality Attributes of Acid Beers. Lorenzo C. Peyer, Martin Zarnkow, Fritz Jacob, David P. Schutter, Elke K. Arendt. 2017.]</ref>.

Most ''Lactobacillus'' species have a thermal death rate of ~145°F 151°F (63°C66°C) after 5 minutes <ref>[https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1957.tb02903.x SOME INVESTIGATIONSON LACTOBACILLUS INFECTION. By R.T.Dean,M.Sc.(Carllon and United Breweries,Ltd.,Melbourne,Australia). Received 11th October,1956.]</ref>. Freezing without glycerol will kill most cells, but it is possible for a very small number of cold-resistant mutant cells to survive <ref>[http://fermentationnation.net/2015/11/episode-26-quality-assurance-w-jessica-davis-of-the-bruery/ Fermentation nation Podcast interview with Jessica Davis, QA for The Bruery.]</ref> (~1:19:00 in). Some In very rare occasions, some strains have been identified as being extremely thermotolerant. For example, for example [https://patents.google.com/patent/US20180042256A1/en this patent] claims that a strain of ''Lactobacillus delbrueckii'' subsp. ''lactis'' can acidify milk within 2.5 hours when held at temperatures between 45-65°C (113-149°F). In another example, [https://sfamjournals.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2672.1999.00607.x Jordan and Cogan (1999)] described the heat tolerance of three strains of ''Lactobacillus'' isolated from cheese (two strains of ''L. plantarum'' and one strain of ''L. paracasei''). When temperatures were finally able to kill the strains, they observed a non-linear death curve with either very little death for the first 15 minuets, or a tailing of the curve. For the ''L. paracasei'' strain, the culture was able to survive temperatures between 50 and 55°C for two hours. At 60°C, there was no significant cell death for 15 minutes, but after 15 minutes the culture began to slowly die, and then more quickly die after an hour of heat exposure. At 65°C, the ''L. paracasei'' strain had a fairly steep death curve for the first 10 minutes, and then a tailing curve showing a small number of cells surviving up to 25 minutes. Even at 72°C, which is typical for pasteurization in the milk industry, the death rate for this strain was slow enough to survive 15 second pasteurization methods. The two strains of ''L. plantarum'' were less heat tolerant, with death starting to occur at around 50-56°C <ref>[https://pubmed.ncbi.nlm.nih.gov/10499302/ Jordan KN, Cogan TM. Heat resistance of Lactobacillus spp. isolated from Cheddar cheese. Lett Appl Microbiol. 1999 Aug;29(2):136-40. doi: 10.1046/j.1365-2672.1999.00607.x. PMID: 10499302.]</ref>. Assuming the heat penetrates all surfaces, exposure to water heated to 72-80°C for 1 minute should be more than adequate for eliminating heat tolerant strains of ''Lactobacillus'', as well as any other beer contaminate species, from the brewing environment. See also:* [[Quality_Assurance#Pasteurization|Pasteurization]]* [[Barrel#Sanitizing|Barrel Sanitizing]]

Major microbe labs will often store bacteria in a -80°C laboratory freezer in a media/glycerol solution (any standard media and 20-50% glycerol <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2710723275622536/?comment_id=2712853618742835&comment_tracking=%7B%22tn%22%3A%22R%22%7D Dr. Bryan Heit, Shawn Savuto, and Dr. Matt Humbard. Milk The Funk Facebook post about storing bacteria with glycerol. 06/08/2019.]</ref>), however, this option is generally not practical for brewers. For dried ''Lactobacillus'', such as probiotics or [[Dry Yeast for Sour Ales BlackManYeast]] products, [http://suigenerisbrewing.blogspot.com/ Bryan of Sui Generis Blog's] states that lab studies have shown that they can lose viability ~80 times faster at room temperature than when stored at refrigeration temperatures. Therefore, it is recommended to store dried ''Lactobacillus'' at refrigeration temperatures. Short term storage of liquid cultures (less than 2 months) should also be stored refrigerated. Consider making a starter before using a culture that is not fresh.

A practical option for brewers without a pressure cooker is to store the liquid culture with a few grams of a buffering chemical such as calcium carbonate (chalk), potassium phosphate, calcium sulfate (gypsum), or calcium hydroxide (pickling lime). The exact amounts should be adjusted to reach a pH of about 4.0-6.0 for the entire solution (begin with 1 or 2 grams per liter, and adjust as needed) <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1095449350483278/?comment_id=1095492120479001&offset=0&total_comments=23&comment_tracking=%7B%22tn%22%3A%22R6%22%7D Conversation with Adi Hastings on MTF. 6/20/2015.]</ref>.

''Lactobacillus'' species can be isolated on agar plates by using a selective media called Rogosa SL. Rogosa SL agar contains ammonium citrate, sodium acetate, a relatively low pH, and acetic acid, which select for ''Lactobacillus'' while inhibiting mold and other bacteria. This medium will not inhibit yeast on its own, however. If inhibiting yeast is a requirement then add 10 mg/L cycloheximide to inhibit most yeast <ref>[https://web.archive.org/web/20160508021144/http://basementbrewlab.com/lab/lab-media/sla/ Rogosa SL Agar (Lactobacillus). Basement Brew Lab. Dustin MetzgerMichael. Retrieved 12/23/2015.]</ref>.

* See [https://web.archive.org/web/20160508021144/http://basementbrewlab.com/lab/lab-media/sla/ Rogosa SL Agar (Lactobacillus); Basement Brew Lab, by Dustin Metzger] for more information.

The presence of ''Lactobacillus'' can stall have an impact on ''S. cerevisiae'' metabolism and the flavor-contributing metabolites that it produces. A study by [https://onlinelibrary.wiley.com/doi/10.1002/jib.569 Dysvik et al. (2019)] compared beer pre-soured with ''L buchneri'' versus pre-soured with lactic acid versus lactic acid added post yeast fermentation and found that lactic acid by itself did not significantly change the amount of volatile flavor compounds produced by the yeast strain that was tested (Fermentis US-05). However, the beers soured with ''L. buchneri'' had significantly different volatile alcohols compared to the beers with just lactic acid added to them. Specifically, the beer that was pre-soured with ''L. buchneri'' ended up with less 2-methyl-1-butanol (alcohol, malty notes), 2-methyl-1-propanol (fruity/winey) and phenylethyl alcohol (rose/honey). The esters ethyl heptanoate and ethyl octanoate where highest when the ''L. buchneri'' pre-soured the wort but was left alive rather than boiled and killed. Acetic acid was also much higher in the beers soured with ''L. buchneri'' versus the beers with just lactic acid added, but the acetic acid was still below flavor threshold. Formic acid was around twice as much in the wort soured with ''L. buchneri'' versus wort with lactic acid or slow no lactic acid/bacteria, but the formic acid disappeared completely in all of the beers tested at bottling time and after maturation in the bottle. Although this study used a neutral ale yeast fermentation(US-05) and alcohols/esters across all samples were below flavor threshold (although combinations of different alcohols/esters under threshold can have a synergistic flavor impact), this supports anecdotal reports from brewers that adding lactic acid to beer to make a sour beer does not produce the same beer than when the souring is done with ''Lactobacillus''. This It is likely a combination interesting to note that both the beers with ''L buchneri'' and the beers with just lactic acid added had similarly significantly lower levels of low pH pyruvic acid compared to the beer fermented with just yeast, as well as less haze, indicating that lactic acid alone inhibits the ability amount of lactic pyruvic acid to change produced by the yeast as well as haze (perhaps because a lower pH reduces protein-polyphenol haze formation, or maybe the way lower pH increased yeast fermentsflocculation) <ref name="Dysvik_2019">[https://onlinelibrary.wiley.com/doi/10.1002/jib.569 Pre‐fermentation with lactic acid bacteria in sour beer production. NormallyAnna Dysvik, Kristian Hovde Liland, Kristine S. Myhrer, Bjørge Westereng, Elling‐Olav Rukke, Gert de Rouck, yeast will ferment glucose first Trude Wicklund. 2019. DOI: https://doi.org/10.1002/jib.569.]</ref>.  This study also compared two pre-soured beers with ''L buchneri'' where one was boiled and hopped after souring and the other was not boiled but instead blended with hoppy wort before fermentation (the viability of the ''L. buchneri'' was greatly reduced in the beer that was blended with hoppy wort, but not completely killed as was the case for the kettle soured beer). The beer that was blended with hoppy wort ended up having the most acetic acid (still below threshold), and the highest level of fruity tasting esters: ethyl heptanoate and ethyl octanoate, indicating that if the ''Lactobacillus'' is allowed to live then it can contribute to more complexity over time. There were no differences in any other sugars of the beers as far as ethanol production or CO₂ production, and terminal acid shock did not occur (probably because the beers were only 4% ABV and 3.6 pH as opposed to the 8.4% ABV and 3.17 pH of the beer tested in the [[Saccharomyces#Fermentation_Under_Low_pH_Conditions|terminal acid shock study by Rogers et al.]]). It is important to note that are also availablethe overall sensory differences reported in this study between the beers soured with ''L. buchneri'' and the beers soured with lactic acid were minor from a statistical analysis point of view <ref name="Dysvik_2019" />.  Souring wort with ''Lactobacillus'' can stall or slow a sequential yeast fermentation. This is likely due to low pH. The presence of lactic acid appears to might change the way yeast ferments by allowing them to consume multiple types of sugars regardless of whether or not glucose is present. See , although it has been demonstrated that this alone is not the cause for stuck fermentations (see [[Lactic Acid]] for more information). Peyer et al. (2017) observed that growth of US-05 was 82% at a pH of 3.51, and 53% at a pH of 3.17. Fermentation was delayed by 2-4 days (the lower the pH, the longer the start of fermentation was delayed). In a co-fermentation of ''Lactobacillus amylovorus'' and US-05, the initial growth of the ''L. amylovorus'' continued for 3 days while the US-05 was delayed. On day 7, the US-05 recovered and continued growth, and the growth of the ''Lactobacillus'' was slowed starting on day 5. This was due to the increase in ethanol from fermentation, lower pH, and the depletion of nutrients for the ''Lactobacillus''. It is also possible that the yeast benefited from the autolysis of the ''Lactobacillus'', which is speculated to have released nutrients that were made available to the yeast <ref name="Peyer_2017" />. Santeri Tenhovirta's master thesis agreed with this. Tenhovirta pitched several species of ''Lactobacillus'' for 48 hours, and then pitched Fermentis US-05. The control US-05 fermentation without any ''Lactobacillus'' started to ferment as expected after 20 hours, while the samples that were pre-acidified with ''Lactobacillus'' took around 2 days to begin yeast fermentation <ref name="Tenhovirta_masters">[https://helda.helsinki.fi/handle/10138/303018 The Effects of Lactic Acid Bacteria Species on Properties of Sour Beer. Santeri Tenhovirta; master thesis in Food Science from the University of Helsinki. 2019.]</ref>.  Ciosek et al. (2019) observed the opposite effect. A faster fermentation was achieved when pitching ''Lactobacillus brevis'' WLP672 (White Labs Inc, USA) for 1, 2, or 3 days before pitching Fermentis Safale US-05. However, the yeast reached a slightly higher final gravity after 7 days and the yeast growth was lower than when the yeast was pitched first or at the same time as the WLP672 ''L. brevis''. Interestingly, the lowest final gravity was achieved when the yeast and ''L. brevis'' were pitched at the same time. This indicates that some species of ''Lactobacillus'' can have a synergistic effect on yeast, while other species might be more antagonistic towards yeast, and that multiple stress factors such as a combination of both low pH and the presence of ethanol can be factors that prevent yeast from attenuating as well as it would have done if the pH wasn't lowered by the presence of lactic acid. Another surprising observation was made by Ciosek et al. (2019) for the samples that were fermented with US-05 first, and then after 1, 2, or 3 days the WLP672 ''L. brevis'' was added and allowed to ferment for 7 days total: these samples did not have a significant drop in pH from the ''L. brevis'', and remained at a pH of 4.0 or higher. This result indicates that this particular strain does not produce much lactic acid in the presence of ethanol or there aren't enough simple sugars left after the yeast fermentation (at least in the short amount of time that they were tested). When the ''L. brevis'' was pitched first, it took 72 hours for the pH to get lower than 4, but this approach ended up with the lowest final pH after yeast fermentation was finished (~3.4 pH), and the co-pitch ended up at ~3.7 pH. The researchers declared that only when the ''L. brevis'' was allowed to ferment by itself for 2-3 days before the yeast was pitched did the finished beers have enough lactic acid content to be considered "sour beer" (~6 g/l of lactic acid for the samples fermented with ''L. brevis'' first versus 1.8-2.8 g/l for all of the other samples), which is based on a definition from "American Sour Beers" by Michael Tonsmeire that states that sour beers are defined as having 3-6 g/l of lactic acid. However, no sensory data was presented in this study, nor were [[Titratable_Acidity|titratable acidity]] measurements taken, and Methner's 1987 thesis on Berliner Weisse reported 1-3 g/l of lactic acid in a survey of these German sour beers, so it is conceivable that all of the sample beers in this study had an adequate sour flavor <ref name="Ciosek_2019">[https://onlinelibrary.wiley.com/doi/pdf/10.1002/jib.590 Sour beer production: impact of pitching sequence of yeast and lactic acid bacteria. Aneta Ciosek, Iga Rusiecka, Aleksander Poreda. 2019. DOI: https://doi.org/10.1002/jib.590.]</ref><ref>[http://herr-rausch.de/MethnerBerliner.pdf Methner's thesis on Berliner Weisse, 1987 (German). Retrieve 11/15/2019.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/3052332944794899/?comment_id=3053207211374139 Benedicth Koch. Milk The Funk Facebook group thread on the lactic acid content of Berliner Weisse. 11/15/2019.]</ref>.

Also found in the Peyer et alstudy was an increase in [https://en. (2017) observed that growth of US-05 was 82% at a pH of 3wikipedia.51, org/wiki/Diacetyl diacetyl] and 53% at a pH of 3[https://en.17wikipedia. Fermentation was delayed by 2-4 days (org/wiki/Acetoin acetoin] in the lower the pH, the longer the start of fermentation was delayed). In a beers that were co-fermentation of fermented with ''Lactobacillus L. amylovorus'' and US-05, versus the initial growth beers that were kettle soured or mash soured. Both of the ''L. amylovorus'' continued these compounds are responsible for 3 days while the US-05 was delayedbuttery taste in beer. On day 7Normally, after primary fermentation the US-05 recovered and continued growthyeast reduces diacetyl to acetoin, and the growth of the ''Lactobacillus'' was slowed starting on day 5. This was due which is then converted to the increase in ethanol from butanediol, however during a co-fermentation, lower pH, and the depletion of nutrients for the ''Lactobacillus''. It is also possible that the yeast benefited from the autolysis of the with ''Lactobacillus'', which is speculated to have released nutrients that were made available to the yeast this conversion was inhibited in this study <ref name="Peyer_2017" />.

Also found was an increase Sensorily speaking, the kettle soured beer in [https://enthe Peyer study tasted "purer" with fewer off-flavors and a plum-like aroma.wikipedia.org/wiki/Diacetyl diacetyl] The sour mash and [https://en.wikipedia.org/wiki/Acetoin acetoin] in kettle sour beers had a lingering sour aftertaste, while the beers that were beer co-fermented with ''L. amylovorus'' and US-05 versus the beers that were kettle soured or mash souredwas described as having an astringent aftertaste. Both of these compounds are responsible for This astringent aftertaste was speculated by the buttery taste in beer. Normally, after primary fermentation the yeast reduces daicetyl authors to acetoinbe caused by LAB cell autolysis, which is then converted might have also contributed to butanediol, however during a more complex flavor profile in the co-fermentation with ''Lactobacillus'', this conversion was inhibited in this study fermented beer <ref name="Peyer_2017" />.

Sensorily speaking, the kettle soured beer tasted "Studies looking at how ''Lactobacillus'' might impact more pure" with less off-flavors, and a plum-like aroma. The sour mash and kettle sour beers had a lingering sour aftertaste, while the beer co-fermented with characterful strains of ''LS. amylovoruscerevisiae'' and US-05 was described , such as having an astringent aftertaste. This astringent aftertaste was speculated by the authors to be caused by LAB cell autlysisBelgian strains, which might have not been done yet. See also contributed to a more complex flavor profile in :* [https://www.facebook.com/groups/MilkTheFunk/permalink/1739694606058746/ Poster for the coreferenced Peyer study.]* [[Mixed_Fermentation#Staggered_Versus_Co-fermented beer <ref name="Peyer_2017" />Pitching|Mixed Fermentation Staggered vs Co-pitching]].* [[Mixed_Fermentation#Souring_Without_Brettanomyces|Mixed Fermentation without ''Brettanomyces'']].

All data provided by [http://phdinbeer.com/2015/08/05/beer-microbiology-lactobacillus-ph-expeirment/ Matt Humbard]. Similar results were reported by Lance Shaner's [[Lactobacillus_Fermentation|100% Lactobacillus Fermentation]] experiment. See also the associated [https://byo.com/article/brewing-with-lactobacillus/ write up in BYO Magazine].

Heterolactic metabolism is described as the cell catabolizing one molecule of glucose into one molecule of CO2CO₂, one molecule of glyceraldehyde phosphate, and one molecule of acetyl phosphate. The molecule of glyceraldehyde phosphate is reduced to one molecule of lactate, and the acetyl phosphate is reduced to one molecule of ethanol (or one molecule of acetic acid instead of ethanol, depending on its growing environment <ref name="Raunak">[https://raunakms.wordpress.com/2011/01/30/lactic-acid-bacteria/ Lactic Acid Bacteria. Raunak Shrestha. Retrieved 6/7/2015.]</ref>). Heterolactic fermentation allows the fermentation of hexoses and pentoses <ref>[https://books.google.com/books?id=eZjIfud742wC&pg=PA33&lpg=PA33&dq=facultative+heterofermentative&source=bl&ots=QQYpzpsrvC&sig=kkyP7wUjgWiE2UV2qkIaRyxMMGA&hl=en&sa=X&ei=K_d0VYDJPLX9sATv_IXgAQ&ved=0CDIQ6AEwBDgK#v=onepage&q=facultative%20heterofermentative&f=false Handbook of Dough Fermentations. Karel Kulp, Klaus Lorenz. CRC Press, May 20, 2003. Pg 33.]</ref>. Heterolactic fermentation follows the Phosphoketolase Pathway, which is a branch of the Pentose Phosphate Pathway (also called the "Phosphogluconate Pathway") <ref name="Effects on Food Properties"></ref><ref>[https://books.google.com/books?id=ZKzzCAAAQBAJ&pg=PA157&lpg=PA157&dq=is+Pentose+Phosphate+Pathway+pathway+the+same+as+phosphoketolase+pathway&source=bl&ots=5-uJY2vpKx&sig=Q-2yFtjWIXGXQnZvgvWZ66OayGc&hl=en&sa=X&ved=0ahUKEwix0fmi64HKAhUI82MKHQMzDcsQ6AEINTAE#v=onepage&q=is%20Pentose%20Phosphate%20Pathway%20pathway%20the%20same%20as%20phosphoketolase%20pathway&f=false Understanding Bacteria. S. Srivastava. 2013. Pg 157.]</ref><ref>[http://textbookofbacteriology.net/metabolism_3.html Todar's Online Textbook of Bacteriology. Diversity of Metabolism in Procaryotes (page 3). Retrieved 12/29/2015.]</ref><ref>[https://books.google.com/books?id=CKEgLmqfbRQC&pg=PA180&lpg=PA180&dq=is+Pentose+Phosphate+Pathway+pathway+the+same+as+phosphoketolase+pathway&source=bl&ots=p_01NAx1Aq&sig=wijMw9u4nBJ2oiH0JjHZfSxrgPU&hl=en&sa=X&ved=0ahUKEwix0fmi64HKAhUI82MKHQMzDcsQ6AEIMjAD#v=onepage&q=is%20Pentose%20Phosphate%20Pathway%20pathway%20the%20same%20as%20phosphoketolase%20pathway&f=false Microbiology. Daniel V. Lim. 2003. Pg 180.]</ref>. When different substrates are available to heterolactic fermenting ''Lactobacillus'', such as fructose or oxygen, acetate (acetic acid) can be produced instead of ethanol <ref name="Peyer"></ref>. It has been observed for at least one strain of ''L. brevis'', which only performs heterolactic fermentation, that the amount of CO₂ produced by this fermentation in brewer's wort was negligible. This is most likely due to the small amount of sugar consumed by ''Lactobacillus'' <ref name="Ciosek_2019" />. See [[Lactobacillus#100.25_Lactobacillus_Fermentation|100% ''Lactobacillus'' fermentation]] for more information.

| L. acidophilus || L. brevis || L. casei <ref name="Toh_2013">[https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0075073 Genomic Adaptation of the Lactobacillus casei Group. Toh et al. 2013.]</ref>

| L. leichmannii <ref name="fao"></ref> || L. confusus <ref name="fao"></ref> || L. paracasei <ref name="Toh_2013" />

A small number of strains of ''Lactobacillus'' can also break down polysaccharides and starches. They are referred to as "amylolytic LAB". They generally belong to the species ''Lb. manihotivorans'', ''L. fermentum'', ''L. amylovorus'', ''L. amylophilus'', ''L. plantarum'' or ''L. amylolyticus''. This seems to be associated with a gene called "amyA", which encodes for extracellular alpha-amylase activity, as well as alpha-glucosidase, neopullulanase, amylopectin phosphorylase, and maltose phosphorylase. This activity is limited by high amounts of glucose, maltose, or sucrose <ref name="peyer_review"></ref>. Some species can also produce beta-glucosidase capable of breaking down monoglycosides (see [[Glycosides]]), or beta-galactosidase which breaks down lactose and other [https://en.wikipedia.org/wiki/Galactoside galactocides], but not diglycosides. The activity of both alpha and beta-glucosidase enzymes are stable at low pH ranges of 3-4, are generally encouraged by increasing percentages of alcohol all the way up to 12% v/v, and are optimal at 35-45°C (depending on strain) <ref>[http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2672.2005.02707.x/full Screening of Lactobacillus spp. and Pediococcus spp. for glycosidase activities that are important in oenology. A. Grimaldi, E. Bartowsky, V. Jiranek. 2005. DOI: 10.1111/j.1365-2672.2005.02707.x.]</ref><ref>[http://www.foodandnutritionjournal.org/volume8number3/effect-of-nutritional-factors-on-growth-behaviour-proteolytic-%CE%B2-glucosidase-and-%CE%B2-galactosidase-activities-of-lactobacillus-cultures-during-soy-drink-fermentation/ Effect of Nutritional Factors on Growth Behaviour, Proteolytic, β-Glucosidase and β-Galactosidase Activities of Lactobacillus Cultures during Soy-Drink Fermentation. Sujit Das, Birendra Kumar Mishra, and Subrota Hati. 2020.]</ref>.

====100% ''Lactobacillus '' Fermentation====

Lance Shaner's experiment on testing [[Lactobacillus_Fermentation|100% Lactobacillus Fermentation]] showed that '''pure cultures''' of WLP677, WLP672, Wyeast 5335, Wyeast 5223-PC, and the ''L. plantarum'' from Omega Yeast OYL-605, could not fully attenuate a 1.037 SG wort. The most attenuative ''Lactobacillus'' culture, WLP677, was only able to attenuate down to 1.03255 SG. It is likely that all species and strains of ''Lactobacillus'' available to brewers cannot fully attenuate wort. In addition, this study showed at most a 0.29% ABV in 100% ''Lactobacillus'' fermentations (attributed to WLP677). See [[Lactobacillus_Fermentation|100% Lactobacillus Fermentation]] for more information. If a higher attenuation is achieved, cross contamination of yeast is most likely the cause. Thomas Hübbe's masters thesis also supports that ''Lactobacillus'' attenuates less than 10% of the sugars in wort <ref name="Hubbe"></ref>.

Recent studies on lactic acid fermented malt beverages also support that ''Lactobacillus'' produces only about 0.1% ABV, producing "non-alcoholic" fermented malt beverages <ref name="Dongmo" /><ref name="Peyer" /><ref name="Tenhovirta_masters" />. Elde Elke Arendt, a brewing scientist that specializes in ''Lactobacillus'' presented her work at the Belgian Brewing Conference 2015. In it she explained that LAB will only ferment 0.5°P of wort regardless of the gravity of that wort. When asked at the end of the presentation why ''Lactobacillus'' only ferments ~0.5°P (note that Shaner's experiment shows ''Lactobacillus'' fermenting ~1°P, although this may be due to a margin of error since Shaner only performed this experiment once), considering that ''Lactobacillus'' ferments maltose and there is plenty of maltose in wort, Arendt responded that she believes that the bacteria reaches max cell density in the wort with relatively little sugar requirements (~16 mins in and ~25 mins in):

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An in-house experiment by Bell's Brewery which was presented at the MBAA Conference 2017 by Timothy Lozen reported slightly higher amoutns of ABV from a few species of ''Lactobacillus''. Out of 7 different species of ''Lactobacillus'' that were tested, ''L. bucherni'' (White Labs) produced the most alcohol at 0.64% ABV. ''L. rossiae'' (White Labs) and ''L. brevis'' (Bell's Brewery) produced around 0.4% ABV. ''L. delbruekii'' subsp. ''bulgaricus'' (ATCC #11842) produced around 0.5% ABV. The other strains, which were ''L. delbruekii'' subsp. ''lactis'' (ATCC #12315), ''L. casei'' (White Labs), and ''L. plantarum'' (Goodbelly) produced 0.1% or lower ABV <ref name="lozen_2017" />. * See also [[Lactobacillus_Fermentation|100% Lactobacillus Fermentation]].

Lactic acid is the primary metabolite for ''Lactobacillus'', as well as CO2 and ethanol/acetate (acetic acid) in heterofermentative species. Acid production is at it's highest during the exponential growth phase, but continues into the stationary and decline phases. Typically just under 50% of the lactic acid produced is L-lactic acid (more nutritionally relevant) while the slight majority is D-lactic acid <ref name="Peyer"></ref>. The amount of lactic and acetic acids produced varies from species to species. For example, the referenced study showed that ''L. plantarum'' produces more than twice the amount of lactic acid than ''L. brevis'', and ''L. reuteri'' produced slightly more lactic acid than ''L. brevis''. ''L. reuteri'' produced around twice as much acetic acid than ''L. brevis'', and ''L. plantarum'' produced very little acetic acid. The small amount of acetic acid produced by ''L. plantarum'' in this study was explained by oxygen exposure during sampling, while the obligate heterofermentative species (''L. reuteri'' and ''L. brevis'') produced acetic acid as a direct result of their heterolactic fermentation <ref name="Peyer"></ref>. Santeri Tenhovirta's master thesis where he soured wort with several species of ''Lactobacillus'' without purging the air out of the headspace, followed by fermenting it unpasteurized with US-05, reported 8 mg/ml of lactic acid in the ''L. rhamnosus'' sample, 7 mg/ml in the ''L. plantarum'' and ''L. alimentarius'' samples, and 5 mg/ml in the ''L. brevis'' and ''L. buchneri'' samples. None of the samples had significant acetic acid production, except for ''L. brevis'' which produced 0.3 mg/ml and the ''L. buchneri'' which produced 1.3 mg/ml <ref name="Tenhovirta_masters" />.

Both primary and secondary metabolites play a large role in the flavor and aroma profile of wort fermented with ''Lactobacillus''. Secondary metabolites are compounds that are not directly related to the growth of an organism, but often assist with survival <ref>[http://www.ncbi.nlm.nih.gov/pubmed/11036689 The natural functions of secondary metabolites. Demain AL, Fang A. 2000.]</ref>. These secondary metabolites are produced by the pathways mentioned above, and different strains probably regulate the enzymes involved in various pathways differently and produce different secondary metabolites <ref>Private correspondence with Richard Preiss from Dan Pixley. 12/29/2015.</ref>. Thus, different species and strains can produce a wide variety of flavors and aromas (compare this to food grade lactic acid in which none of these secondary metabolites exist). These secondary metabolite are the result of carbohydrate fermentation and amino acid metabolism <ref name="peyer_review"></ref>. Major secondary metabolites Different species can have varying ranges of flavor intensities, especially citrus flavor, which one study that soured wort and then fermented with US-05 two days later (not kettle soured) reported was higher for ''L. plantarum'', ''L. alimentarius'', ''L. brevis'', and ''L. buchneri'' versus ''L. rhamnosus''. Vinuous, malty, and sour flavors were also reported to vary in intensity based on species. ''L. buchneri'' was reported in the study to be the most vinuous, followed by (in descending order of intensity) ''L. brevis'', ''L. plantarum'', and ''L. alimentarius''. The sour flavor was reported highest for ''L. plantarum'' and ''L. alimentarius'', followed by (in descending order of intensity) ''L. brevis'', ''L. buchneri'', and finally ''L. rhamnosus''. ''L. rhamnosus'' had the most raspberry flavor, while the other species had a similar level of moderate raspberry flavor. All of the species tested had similar levels of apple flavor (moderate), acetic flavor (low), butyric (very low to absent, even though the fermenting vessels were never purged of oxygen), bitter aftertaste (low), and yeasty (low) <ref name="Tenhovirta_masters" />.

An example in-house experiment at Bell's Brewery by Timothy Lozen demonstrated similar flavor differences in wort soured with a selection of different strains: ''L. brevis'' from one study showed that Bell's Brewery, ''L. plantarumcasei'' (White Labs), ''L. buchneri'' produced significantly more diacetyl(White Labs), acetoin ''L. delbruekii'' subsp. ''bulgarius'' (yogurt-like flavorATCC #11842), and acetaldehyde than ''L. reuteriplantarum'' (Goodbelly), and ''L. brevisrossiae''(White Labs). These three compounds were associated The wort soured with dairy-related notes of "buttery", "lactic", and "yogurt" flavors identified during sensory testing <ref name="Peyer"></ref>''L. Some LAB can release these compounds through bucherni'' was the catabolism most preferred with a score of citric acid5.9, followed closely by ''L. casei'' which is found in wortscored 5. Ester production is generally insignificant3, although significant ester formation has been found during malolactic fermentation in red wines, and ethyl acetate has been found to be produced in malt based beverages <ref name="peyer_review">[http://www''L.sciencedirectbrevis'' wich scored 4.com/science/article/pii/S0924224415300625 Lactic Acid Bacteria as Sensory Biomodulators for Fermented Cereal-Based Beverages9, ''L. Lorenzo Cplantarum'' which scored 4. Peyer 6, Emanuele Zannini , Elke Kand ''L. rossiae'' which scored 4. Arendt3. 2016The ''L.]</ref>. Acetaldehyde produced from delbruekii''Lsubsp. plantarum'' helps to produce pyranoanthocyanins that stabilize winebulgarius''s red color <ref>[https://www.sciencedirect.com/science/article/pii/S0963996918302084 Acetaldehyde released by Lactobacillus plantarum enhances accumulation scored lowest on preference with a score of pyranoanthocyanins in wine during malolactic fermentation1. Shaoyang Wanga6, Siyu Lic, Hongfei Zhaoa, Pan Gua, Yuqi Chena, Bolin Zhanga, Baoqing Zhu. 2018. https://doi.org/10.1016/j.foodres.2018.03.032]<and was characterized as "cheesy/ref>. Some strains may also produce fusel alcohols pukey and other off-flavorsfunky". For example the referenced study found an accumulation of the fusel alcohol n-Porponal in the sample of ''L. reutericasei''was characterized as the most sour, and a small decrease of isovaleric acid coupled with a small increase of [https://en.wikipedia.org/wiki/Hexanoic_acid hexanoic acid] by while ''L. brevisbuchneri'', was characterized as the most citrusy and ''L. plantarum'', was characterized as the most fruity. The different strains also produced a range of titratable acidity and diacetyl with ''L. reutericasei'' producing the most and '' (only 0L.25-0delbruekii'' subsp.32 mg/L was found, ''bulgarius'' the lowest titratable acidity and the flavor threshold of hexanoic acid is 5most diacetyl.4 mg/ ''L buchneri'' produced the most alcohol at 0.64% ABV <refname="lozen_2017">[httphttps://www.leffingwellmbaa.com/odorthre.htm Leffingwell & Associates website. Odor Thresholds. Retrieved 12meetings/archive/302017/2015.]<proceedings/ref>) <ref name="Peyer"><Pages/ref>92.aspx Timothy Lozen. Heterofermentative species can also produce [[Tetrahydropyridine|tetrahydropyridines (THP)]], which is the cause of "mousy" off-flavors <ref name="Costello">[http://pubs.acs.org/doi/abs/10.1021/jf020341r Mousy Off-Flavor A comparison of Wine:  Precursors and Biosynthesis selected lactic acid bacteria for use in the production of the Causative N-Heterocycles 2-Ethyltetrahydropyridine, 2-Acetyltetrahydropyridine, sour wort and 2-Acetyl-1-pyrroline by Lactobacillus hilgardii DSM 20176beer. " Peter J. Costello and Paul A. HenschkePresentation by Bell's Brewery for the 2017 Master Brewers Conference. 20022017.]</ref>. Aldehydes (2-methyl-1-propanal, 2-methyl-1-butanal, 3-methyl-1-butanal) and their associated non-fusel alcohols (2-methyl-1-propanol, 2-methyl-1-butanol, and 3-methyl-1-butanol) can be produced from amino acids such as leucine, isoleucine, and valine to form fruity flavors <ref name="peyer_review"><See also [https://ref>www. A few species, especially most strains of ''Lmasterbrewerspodcast. fermentum'', and some strains of ''L. delbrueckii subsp. bulgaricus'', can produce ropiness in the form of exopolysaccharides, similar to [[Pediococcus]com/085 MBAA podcast #85 with Tim Lozen] <ref name="peyer_review"></ref>.

[http://www.sciencedirect.com/science/article/pii/S0308814617302911#t0005 Dongmo et al. (2017)] found 56 volatile flavor compounds, including various esters, alcohols, ketones, aldehydes, acids, ethers compounds, sulfur compounds, heterocyclic compounds, phenols (including guaiacol and 4-vinylguaiacol), terpenes, lactones, and several unidentified compounds. Key compounds produced by Another study showed that ''LactobacillusL. plantarum'' include acetaldehyde produced significantly more diacetyl, acetoin (thought to be a major yogurt-like flavor contributor to kettle soured beers <ref name="Peyer_2017" />), β-Damascenone, furaneol, phenylacetic acid, 2-phenylethanol, 4-vinylguaiacol, sotolon, methional, vanillin, acetic acid, nor-furaneol, guaiacol and ethyl 2-methylbutanoate. Acetaldehyde was the most impactful aroma compound found followed by propan-1-ol and γ-dodecalactone. Acetaldehyde was generally produced in much higher amounts (~23-64 µg/L) by the select strains of acetaldehyde than ''L. plantarum'', while ''L. amylolyticusreuteri'' and ''L. brevis'' produced only 1.5 These three compounds were associated with dairy-3 µgrelated notes of "buttery", "lactic", and "yogurt" flavors identified during sensory testing <ref name="Peyer"></Lref>. In fact, the levels of all of Some LAB can release these compounds differed significantly based on through the species and strain. The selected strains catabolism of ''Lcitric acid, which is found in wort. brevis'' were associated as having worse aromas that were dominated by methional (cooked potatoes) Ester production is generally insignificant, acetic acid (vinegar)although significant ester formation has been found during malolactic fermentation in red wines, and norethyl acetate has been found to be produced in malt based beverages <ref name="peyer_review">[http://www.sciencedirect.com/science/article/pii/S0924224415300625 Lactic Acid Bacteria as Sensory Biomodulators for Fermented Cereal-furaneol (caramel-like)Based Beverages. The ''LLorenzo C. plantarum'' strains selected were identified as producing more positive aromas from compounds such as β-damascenone (apple/fruit juice)Peyer , furaneol (strawberry)Emanuele Zannini , 2-phenylethanol (rose/caramel) and ethyl 2-methylbutanoate (citrus) Elke K. Arendt. Small but significant amounts of linalool and geraniol were also found, which are normally terpenes found in [[Hops|hops]2016.]</ref><ref name="Tenhovirta_masters" />. Vanillan is formed Acetaldehyde produced from ferulic acid by some ''LactobacillusL. plantarum'' species as well as ''Oenococcus oeni'helps to produce pyranoanthocyanins that stabilize wine' s red color <ref name="Dongmo">[httphttps://www.sciencedirect.com/science/article/pii/S0308814617302911 Key volatile aroma compounds S0963996918302084 Acetaldehyde released by Lactobacillus plantarum enhances accumulation of lactic acid fermented malt based beverages – impact of lactic acid bacteria strainspyranoanthocyanins in wine during malolactic fermentation. Sorelle Nsogning DongmoShaoyang Wanga, Siyu Lic, Hongfei Zhaoa, Pan Gua, Bertram SacherYuqi Chena, Hubert KollmannsbergerBolin Zhanga, Thomas BeckerBaoqing Zhu. 20172018. doi:httphttps://dx.doi.org/10.1016/j.foodchemfoodres.20172018.02.09103.032]</ref>. Some strains may also produce fusel alcohols and other off-flavors. For example the referenced study found an accumulation of the fusel alcohol n-Porponal in the sample of ''LactobacillusL. reuteri'' can break down chlorogenic acids, which are esters found in plants, into their phenolic derivativesand a small decrease of isovaleric acid coupled with a small increase of [https://en.wikipedia. For example, some strains of org/wiki/Hexanoic_acid hexanoic acid] by ''L. fermentumbrevis'', ''L. helveticusplantarum'', and ''L. reuteri'' were (only 0.25-0.32 mg/L was found to hydrolize chlorogenic acids into caffeic acid, which can then be converted into other esters such as 4-vinylcatechol and the flavor threshold of hexanoic acid is 5.4-ethylcatechol by ''mg/L <ref>[http://www.leffingwell.com/odorthre.htm Leffingwell & Associates website. Odor Thresholds. Retrieved 12/30/2015.]</ref>) <ref name="Peyer"></ref>. Heterofermentative species can also produce [[Brettanomyces#Phenol_ProductionTetrahydropyridine|Brettanomycestetrahydropyridines (THP)]]'' , which is the cause of "mousy" off-flavors <refname="Costello">[httpshttp://wwwpubs.sciencedirectacs.comorg/sciencedoi/articleabs/pii10.1021/S0963996918303363 Sitejf020341r Mousy Off-specific hydrolysis Flavor of chlorogenic acids Wine:  Precursors and Biosynthesis of the Causative N-Heterocycles 2-Ethyltetrahydropyridine, 2-Acetyltetrahydropyridine, and 2-Acetyl-1-pyrroline by selected Lactobacillus specieshilgardii DSM 20176. Elsa Anaheim Aguirre Santos, Andreas Schieber, Fabia nWeberPeter J. Costello and Paul A. 2018Henschke. DOI: https://doi2002.org]</10ref>.1016 Aldehydes (2-methyl-1-propanal, 2-methyl-1-butanal, 3-methyl-1-butanal) and their associated non-fusel alcohols (2-methyl-1-propanol, 2-methyl-1-butanol, and 3-methyl-1-butanol) can be produced from amino acids such as leucine, isoleucine, and valine to form fruity flavors <ref name="peyer_review"></jref>.foodres A few species, especially most strains of ''L.2018fermentum'', and some strains of ''L.04.052delbrueckii'' subsp.''bulgaricus'', can produce ropiness in the form of exopolysaccharides, similar to [[Pediococcus]]<ref name="peyer_review"></ref>.

[http://www.sciencedirect.com/science/article/pii/S0308814617302911#t0005 Dongmo et al. (2017)] found 56 volatile flavor compounds, including various esters, alcohols, ketones, aldehydes, acids, ethers compounds, sulfur compounds, heterocyclic compounds, phenols (including guaiacol and 4-vinylguaiacol), terpenes, lactones, and several unidentified compounds. Key compounds produced by ''Lactobacillus'' include acetaldehyde (thought to be a major flavor contributor to kettle soured beers <ref name="Peyer_2017" />), β-Damascenone, furaneol, phenylacetic acid, 2-phenylethanol, 4-vinylguaiacol, sotolon, methional, vanillin, acetic acid, nor-furaneol, guaiacol and ethyl 2-methylbutanoate. Acetaldehyde was the most impactful aroma compound found followed by propan-1-ol and γ-dodecalactone. Acetaldehyde was generally produced in much higher amounts (~23-64 µg/L) by the select strains of ''L. plantarum'', while ''L. amylolyticus'' and ''L. brevis'' produced only 1.5-3 µg/L. In fact, the levels of all of these compounds differed significantly based on the species and strain. The selected strains of ''L. brevis'' were associated as having worse aromas that were dominated by methional (cooked potatoes), acetic acid (vinegar), and nor-furaneol (caramel-like). The ''L. plantarum'' strains selected were identified as producing more positive aromas from compounds such as β-damascenone (apple/fruit juice), furaneol (strawberry), 2-phenylethanol (rose/caramel) and ethyl 2-methylbutanoate (citrus). Small but significant amounts of linalool and geraniol were also found, which are normally terpenes found in [[Hops|hops]]. Vanillan is formed from ferulic acid by some ''Lactobacillus'' species as well as ''Oenococcus oeni'' <ref name="Dongmo">[http://www.sciencedirect.com/science/article/pii/S0308814617302911 Key volatile aroma compounds of lactic acid fermented malt-based beverages – impact of lactic acid bacteria strains. Sorelle Nsogning Dongmo, Bertram Sacher, Hubert Kollmannsberger, Thomas Becker. 2017. doi:http://dx.doi.org/10.1016/j.foodchem.2017.02.091.]</ref>. Some strains of ''Lactobacillus'' can break down chlorogenic acids, which are esters found in plants, into their phenolic derivatives. For example, some strains of ''L. fermentum'', ''L. helveticus'', and ''L. reuteri'' were found to hydrolize chlorogenic acids into caffeic acid, which can then be converted into other phenols such as 4-vinylcatechol and 4-ethylcatechol by ''[[Brettanomyces#Phenol_Production|Brettanomyces]]'' <ref>[https://www.sciencedirect.com/science/article/pii/S0963996918303363 Site-specific hydrolysis of chlorogenic acids by selected Lactobacillus species. Elsa Anaheim Aguirre Santos, Andreas Schieber, Fabian Weber. 2018. DOI: https://doi.org/10.1016/j.foodres.2018.04.052.]</ref>.  Some strains of ''L. plantarum'', ''L. brevis'', and ''Pediococcus pentosaceus'' can reduce hydroxycinnamic acids such as p-coumaric, caffeic, and ferulic acids, into their vinyl phenol derivatives, similar to POF+ ''Saccharomyces'' and ''Brettanomyces''. Furthermore, some strains of ''L. plantarum'' have been found to further reduce the vinyl phenols into ethyl phenols (the same phenolic compounds produced by ''Brettanomyces'') by excreting a protein enzyme called ''VprA''. So far ''L. plantarum'' is the only species of lactic acid yeast that has been identified as being capable of creating ethyl phenols from vinyl phenols, and only certain strains have the genetic capability to do this <ref>[http://aem.asm.org/content/early/2018/06/20/AEM.01064-18.abstract Ethylphenols formation by Lactobacillus plantarum: Identification of the enzyme involved in the reduction of vinylphenols. Laura Santamaría, Inés Reverón, Félix López de Felipe, Blanca de las Rivas and Rosario Muñoz. 2018. doi: 10.1128/AEM.01064-18.]</ref><ref>[https://www.ncbi.nlm.nih.gov/pubmed/25261518 Hydroxycinnamic acids used as external acceptors of electrons: an energetic advantage for strictly heterofermentative lactic acid bacteria. Filannino P, Gobbetti M, De Angelis M, Di Cagno R. 2014. DOI: 10.1128/AEM.02413-14.]</ref>.  The type of grain that the ''Lactobacillus'' is fermented in may also play a role in the types and amounts of secondary metabolites that are produced. One study compared volatile acids produced by a probiotic strain of ''L. plantarum'' (NCIMB 8826) when fermented in oats, barley, malted barley, and wheat. In oats, there was slight increase in oleic acid and linoleic acid and a decrease when fermented in wheat, barley, or malted barley. In malted barley, there were small increases in flavor active compounds such as furfural ("almond" flavor), 2-ethoxyethyl acetate and isoamyl alcohol, but little to none detected when fermented in oats, wheat, or unmalted barley. Acetic acid production was higher in barley and malted barley than it was in oats and wheat. Many other organic acids in the oats, wheat, barley, and malted barley were supposedly taken up by the ''L. plantarum'' during fermentation. In barley, there were trace amounts of new acids created that were not already in the barley itself <ref>[http://www.sciencedirect.com/science/article/pii/S0308814609004373 Volatile compounds produced by the probiotic strain Lactobacillus plantarum NCIMB 8826 in cereal-based substrates Ivan Salmeron, Pablo Fuciños, Dimitris Charalampopoulos, Severino S. Pandiella. 2009.]</ref>. Some species of ''Lactobacillus'', including ''L. lactis'' and ''L. plantarum'', produce diacetyl (which can be reduced to acetoin and 2,3-butanediol) as an intermediate metabolite from consuming sugar, citrate, and amino acids. However, citrate levels are rather low in malted barley (but higher in sorghum), and diacetyl production has been observed to be very low in barley and oat -based worts <ref name="peyer_review"></ref>.

A few species/strains of ''Lactobacillus'' can create all of the amino acids that they need for growth. These species are known as '''prototrophic'''. However, most species/strains can only produce some of the amino acids required for growth and must obtain the other amino acids from their environment. These species are known as '''auxotrophic''' for the amino acids that they cannot produce themselves <ref>[http://www.ncbi.nlm.nih.gov/pubmed/17993552 Phenotypic and genotypic analysis of amino acid auxotrophy in Lactobacillus helveticus CNRZ 32. Christiansen JK, Hughes JE, Welker DL, Rodríguez BT, Steele JL, Broadbent JR. 2007.]</ref>. Auxotrophic ''Lactobacillus'' can break down proteins into simpler amino acids in their environment in order to consume the amino acids that they cannot make themselves, including foam forming proteins in beer, through a process called '''proteolysis''' <ref name="Todar"></ref>. Proteolysis is the breakdown of various proteins into smaller polypeptides or amino acids through the use of various protease enzymes . This process is a large part of cheese and yogurt fermentation <ref>[https://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/26351/ShellhammerThomasH.FoodScience.TextureProteolysisViable.pdf?sequence=1 Texture, proteolysis and viable lactic acid bacteria in commercial Cheddar cheeses treated with high pressure. Cheryl Wick, Uwe Nienaber, Olga Anggraeni, Thomas H Shellhammer and Polly D Courtney. 2002. Retrieved 7/7/2015.]</ref><ref name="Haq_Mukhtar">[http://www.researchgate.net/profile/Hamid_Mukhtar4/publication/230245468_PROTEASE_BIOSYNTHESIS_FROM_LACTOBACILLUS_SPECIES_FERMENTATION_PARAMETERS_AND_KINETICS/links/00b7d52c403b158288000000.pdf Protease Biosynthesis from Lactobacillus Species: Fermentation Parameters and Kinetics. Ikram-Ul_Haq and Hamid Mukhtar. Jan 2007. Retrieved 7/7/2015.] </ref><ref>[https://en.wikipedia.org/wiki/Proteolysis Proteolysis. Wikipedia. Retrieved 7/7/2015.]</ref>. Both homofermentative and heterofermentative species have been observed to have proteolytic activity , and the degree of proteolytic activity differs from strain to strain and even more so from species to species. These differences are most likely due to differences in gene expression as well as differences in optimal conditions between strains and species <ref>[https://www.frontiersin.org/articles/10.3389/fmicb.2018.02354/full Production of Bioactive Peptides by Lactobacillus Species: From Gene to Application. Cyril Raveschot, Benoit Cudennec, François Coutte, Christophe Flahaut, Marc Fremont, Djamel Drider, and Pascal Dhulster. 2018.]</ref><ref>[https://books.google.com/books?id=qMreBwAAQBAJ&pg=PA133&lpg=PA133&dq=lactobacillus+homofermentative+proteolytic&source=bl&ots=bjxq9rGdha&sig=pCz4WeKek3zTv5oL6Rui1dUuEqw&hl=en&sa=X&ei=AJqcVeT0O8XkoAS0-oC4CQ&ved=0CF0Q6AEwBw#v=onepage&q=lactobacillus%20homofermentative%20proteolytic&f=false Brewing Microbiology. Fergus Priest. Springer Science & Business Media, Jun 29, 2013. Pg 133.]</ref>. This process is a large part of cheese and yogurt fermentation. ''Lactobacillus'' species that have been identified as breaking down proteins (mostly in cheese or yogurt) include ''Lactobacillus bulgaricus'', ''Lactobacillus rhamnosus'', ''Lactobacillus casei'', ''Lactobacillus paracasei'', ''Lactobacillus helveticus'', ''Lactobacillus delbrueckii'', ''Lactobacillus brevis'', ''Lactobacillus cellobiosus'', ''Lactobacillus fermentum'', and ''Lactobacillus plantarum'' <ref name="Haq_Mukhtar"></ref>. Results of using various species/strains appears to demonstrate that different species/strains are worse for degrading head retention proteins than others. For example, it's been reported that B.H. Meyer says that souring with ''L. delbruekii'' creates better head retention than souring with other species such as ''L. brevis''. <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1105663546128525/?comment_id=1105772812784265&offset=0&total_comments=107&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Conversation with Kristen England on MTF. 7/7/2015.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1096427697052110/?comment_id=1096496983711848&offset=0&total_comments=45&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Conversation with Jace Marti on MTF about L. delbruekii head retention problems. 6/21/2015.]</ref>. Different strains of the same species may also have different levels of proteolytic activity <ref>[http://www.ncbi.nlm.nih.gov/pubmed/8568030 Comparison of proteolytic activities in various lactobacilli. Sasaki M, Bosman BW, Tan PS. 1995.]</ref>.

Another method that has been reported to help with head retention when [[Sour WortingWort Souring]] (ex., kettle souring) is to add a pound of DME per 5 gallons of wort during the heat pasteurization process (after the wort has been soured with ''Lactobacillus''). One could also steep specialty grains such as wheat malt, chit malt, carafoam, or carapils, and add the extract into the kettle during the heat pasteurization or boiling process. This will add back head formation proteins that were lost during the ''Lactobacillus'' fermentation <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1069228273105386/?comment_id=1069266549768225&offset=0&total_comments=24&comment_tracking=%7B%22tn%22%3A%22R8%22%7D Conversation with Gareth Young on MTF. 05/08/2015.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1137179879643558/?comment_id=1137362989625247&offset=0&total_comments=8&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Paul Finney on MTF in regards to head retention of Berliner Weisse. 08/29/2015.]</ref>.

While most species of ''Lactobacillus'' do not produce bacteriocins, many strains of ''L. acidophilus'' are well known for being able to produce bacteriocins, including probiotics and yogurt strains. Bacteriocins are similar to the [[Saccharomyces#Killer_Wine_Yeast|toxins that some wine yeast strains produce]], ; however, bacteriocins are toxins target other bacteria. The bacteriocin that ''L. acidophilus'' produces is a narrow spectrum class II bacteriocin, '''lactacin B''' ("narrow spectrum" means that this toxin kills a very narrow range of closely related Gram-positive bacteria). Species that are susceptible to the lactacin B toxin include species that are genetically closely related to ''L. acidophilus''. These species include ''L. leichmanii'', ''L. bulgaricus'', ''L. delbruekii'', ''L. lactis'', and ''L. helveticus''. Species that are insensitive to the toxin because they are more distantly related genetically are ''L. plantarum'', ''L. casei'', ''L. viridescens'', and ''L. fermentum''. Some strains of sensitive species might be insensitive to the toxin from certain strains of ''L. acidophilus'' but sensitive to others. The toxin does not affect a wide range of bacteria, nor yeast species <ref>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC242543/ Detection and activity of lactacin B, a bacteriocin produced by Lactobacillus acidophilus. S F Barefoot and T R Klaenhammer. 1983.]</ref><ref>[https://link.springer.com/article/10.1007/s12602-017-9326-2 Lack of Heterogeneity in Bacteriocin Production Across a Selection of Commercial Probiotic Products. J. W. Hegarty, C. M. Guinane, R. P. RossC. Hill, P. D. Cotter. 2017.]</ref>. Some species of ''[[Pediococcus]]'' can also create bacteriocins (see this [https://www.facebook.com/BootlegBiology/photos/a.148869931970401.1073741829.124634287727299/465185997005458/?type=1&theater Bootleg Biology Facebook post]).

Some strains of ''L. plantarum'' cultured from Tibetan yaks have been found to have varying levels of bacteriocin activity as well. These strains produced a "class II enterocin" that inhibits the growth of ''E. coli'' and ''Staphylococcus aureus''. A strain of ''Pediococcus pentocaseus'' was also found to produce this enteriocin <ref>[https://www.sciencedirect.com/science/article/pii/S0882401017314559 Antibacterial activity of Lactobacillus plantarum isolated from Tibetan yaks. Lei Wang, Hui Zhang, Mujeeb Ur Rehman, Khalid Mehmood, Xiong Jiang, Mujahid Iqbal, Xiaole Tong, Xing Gao, Jiakui Li. 2017.]</ref>. One strain of ''L. plantarum'' isolated from kombucha was found to produce a bacteriocin called ''SLG10'' which has a broad spectrum of killing power, including affecting both Gram-positive and Gram-negative bacteria and preventing biofilm formation in other bacteria. This bacteriocin works by increasing the permeability of the cell walls of competing bacteria, which causes the target cells to excrete potassium and eventually die <ref>[https://www.sciencedirect.com/science/article/pii/S0956713519305122 Isolation, purification, and structural identification of a new bacteriocin made by Lactobacillus plantarum found in conventional kombucha. Jinjin Pei, Wengang Jin, A.M.Abd El-Aty, Denis A. Baranenko, Xiaoying Gou, Hongxia Zhang, Jingzhang Geng, Lei Jiang, Dejing Chen, Tianli Yue. 2019.]</ref>. ===Gluten Reduction===In recent years, there has been an increase in the number of people with gluten intolerance or perceived/believed gluten intolerance whose resulting gluten-free diets that are unbalanced from low fat from carbohydrates, and this has lead to research on whether or not ''Lactobacillus'' fermented grain beverages or beers can produce gluten reduced beverages. Some lactic acid bacteria produce specific peptidase enzymes during growth that break down gluten by cleaving bonds between the amino acids in gluten, similar to how lactic acid bacteria can break down head retention proteins (see [[Lactobacillus#Foam_Degradation|Foam Degradation above]]) <ref name="Bradauskiene_2019">[http://agris.fao.org/agris-search/search.do?recordID=LV2019000334 Fermentation with Lactobacillus strains for elimination of gluten in wheat (Triticum aestivum) by-products. Vijole Bradauskiene, Lina Vaiciulyte-Funk, Edita Mazoniene, Darius Cernauskas. 2019. DOI: http://doi.org/10.22616/FoodBalt.2019.029.]</ref>.  Taubman et al. published a paper in the MBAA Technical Quarterly that reported that a strain of ''L. brevis'', ''L. curvatus'', ''L. plantarum'', and ''Pediococcus pentosaceus'' that were found to reduce gluten in sourdough bread making had a similar functionality when fermenting wort. They found that these strains reduced gluten to undetectable levels in 5-7 weeks. However, they lost the ability to reduce gluten when co-fermented with yeast, probably due to competition from the yeast. The wort that was fermented with only one of the lactic acid bacteria strains and no yeast resulted in an unpleasant fermented beverage. The researchers also reported analyzing commercial sour beers and finding some with reduced levels of gluten, but did not offer an explanation on how to accomplish this <ref>[https://www.mbaa.com/publications/tq/tqPastIssues/2018/Pages/TQ-55-1-0305-01.aspx ​Microbial Gluten Reduction in Beer Using Lactic Acid Bacteria and Standard Process Methods. Brett F. Taubman, Stephan Sommer, Jacob Edwards, Travis Laws, Logan Hamm, and Brenton A. Frank. 2018. DOI: https://doi.org/10.1094/TQ-55-1-0305-01.]</ref><ref>[http://masterbrewerspodcast.com/094-microbial-gluten-reduction-in-beer-using-lactic-acid-bacteria-and-standard-process-methods "094: Microbial Gluten Reduction in Beer Using Lactic Acid Bacteria and Standard Process Methods". Master Brewers Association Podcast. June 2018.]</ref>. The researchers hypothesized that the cause of the off-flavors in the 100% ''Lactobacillus'' fermentations were due to oxygen and hydrogen sulfide in the headspace of the fermenters and that further experiments with purging the oxygen and hydrogen sulfide from the head space should be done, however, previous research has shown that wort fermented with only ''Lactobacillus'' does not fully attenuate which leaves ample amounts of residual sugar available for contaminants to potentially produce off-flavors (assuming they can withstand the low pH produced by the lactic acid bacteria fermentation). Performing long fermentations with only ''Lactobacillus'' are generally not recommended due to the residual sugar left by 100% ''Lactobacillus'' fermentation. For example, it is recommended to [[Wort_Souring#Souring_in_the_Boiler_.28Kettle_Sour.29|kettle sour]] within 24-48 hours in order to lower the risk of off-flavor development. Attenuation/ethanol/final gravity measurements were not reported in this study. Another study by [http://agris.fao.org/agris-search/search.do?recordID=LV2019000334 Bradauskiene et al. (2019)] looked at the reduction of gluten by four different probiotic ''Lactobacillus'' strains. They first performed a "wet fractionation" which is a method of separating solids from the liquid wort. This is a method that has been shown to physically remove a portion of gluten from the liquid and is done by centrifuging the wheat/water mixture. Separate fractions of starch, fiber, and bran were obtained and then each separately centrifuged. The centrifuged liquid of each fraction (starch, fiber, and bran) was split into 4 different fermenters and each fermented with a different ''Lactobacillus'' strain (two strains of ''L acidophilus'', one strain of ''L. plantarum'', and one strain of ''L. brevis''). The results of the study showed that different strains reduce gluten by different amounts after 24 hours of fermentation, but overall the amount of gluten reduction was too small to achieve the 20 mg/kg of gluten that is required to label something as "gluten free". The gluten content was reduced by a significant amount in the fiber portion which was initially 7800 mg/kg and went down to 2200-2800 mg/kg depending on the strain used with the greatest reduction by one of the ''L. acidophilus'' strains. The starch portion had low gluten to begin with at 80 mg/kg and was reduced to 12-30 mg/kg. The bran fraction had around 33750 mg/kg, but the gluten reduction was not reported for it. While some strains of ''Lactobacillus'' could be used to make a starch-only containing liquid gluten-free, they were unable to achieve enough gluten reduction with the fiber and bran fractions of wheat <ref name="Bradauskiene_2019" />. ===Probiotics===See [[Alternative Bacteria Sources]]. ===Biogenic Amines===(To do) * [https://www.facebook.com/groups/MilkTheFunk/permalink/3278367452191446/ MTF thread]. See also:* [[Brettanomyces#Biogenic_Amines|Biogenic amines from ''Brettanomyces'']]* [[Spontaneous_Fermentation#Biogenic_Amines|Biogenic amines in lambic]]

* [[Sour WortingWort Souring]]

* [http://phdinbeer.com/2015/08/05/beer-microbiology-lactobacillus-ph-expeirment/ Beer Microbiology – Lactobacillus pH experiment] - Matt Humbard's experiment to determine final pH of individual ''Lactobacillus'' strains used in the graphs on this page. See also the [https://byo.com/article/brewing-with-lactobacillus/ published article in BYO Magazine].