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Lactobacillus

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! Name !! Mfg# !! Taxonomy !! CO2 Producer (Het/Hom) !! Starter Note !! Fermentation/Other Notes
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| [[Bootleg Biology]] || Sour Weapon L || Lactobacillus plantarum (blended strains) || Facultatively heterofermentative || || 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 bacteria blend 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 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>.
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| [[Brewing Science Institute]] || L. delbrueckii || Lactobacillus delbrueckii || Homofermentative || || A Lactobacillus bacteria that produces a clean lactic sourness.
| [[Craft Cultures]] || CCYL512 || L. brevis || Heterofermentative || || Typically produces more lactic acid than Lactobacillus delbrueckii. Commercial pitches only.
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| [[White LabsEscarpment Laboratories]] || WLP677 Lactobacillus Blend || L. delbrueckii (potentially misidentified) brevis and L. plantarum || 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> || no stir plate, room temp ||Incubate This blend is designed to be usable at > 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 35 mL homebrew vial) <ref name="WL_cellcounts">Private correspondence with White Labs Customer Service wide range of temperatures, and Dan Pixley. 10/29/2015.</ref>. Not a good strain is especially suited for kettle souring, but can produce a "soft" acidity over a longer period of time <ref>[https://wwwsour worting.facebookWe recommend pre-acidifying wort to 4.com/groups/MilkTheFunk/permalink/1212455192116026/?comment_id=1212475888780623&reply_comment_id=1212476575447221&comment_tracking=%7B%22tn%22%3A%22R3%22%7D Conversation 5 with Andrew Addkison on MTF. 01/12/2016.]</ref>. White Labs claims that it is tolerant to up to 20 IBU <ref>[http://www.themadfermentationist.com/p/commercial-cultures.html "Commercial Brettanomyceslactic acid, then pitching the Lactobacillus, and Pediococcus Descriptions; Commercial Yeast Laboratories." The Mad Fermentationist blog. Michael Tonsmeire. Retrieved 12/12/2016.]</ref>blend in a CO2-purged kettle or fermentor at 32-42°C.
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| [[White LabsEscarpment Laboratories]] || WLP672 Lactobacillus brevis || L. 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 This strain is moderately hop -tolerant than other Lacto strains, however TYB advises to use wort with less than 10 IBU. Temperature range: 70and as such it can also be used for long-95°F; 80% attenuation (this may not reflect actual attenuation term souring of wort in a real brewery; see reference <ref>[https://www10IBU beers.facebook.com/groups/MilkTheFunk/permalink/1031115430250004/?comment_id=1031244193570461&offset=0&total_comments=33 Conversation with Michael Soo and Nick Impellitteri on the Milk The Funk Facebook Group. 3/5/2015.]</ref>). <ref>[http://www.theyeastbay.comIt also performs well in kettle souring/wild-yeast-sour worting where fast and-bacteria-products/wlp672-lactobacillus-brevis The Yeast Bay website. Retrieved 3/2/2015clean lactic acidity is desired.]</ref> Cell count: 50We recommend pre-80 million cells/mL (1acidifying wort to 4.755 with lactic acid, then pitching the Lactobacillus blend in a CO2-2.8 billion cells for purged kettle or fermentor at 35 mL homebrew vials) <ref name="WL_cellcounts"></ref>-45°C.
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| [[WyeastInland Island Brewing & Consulting|Inland Island Yeast Laboratories]] || 5335 INISBC-991 || L. buchneri brevis || Heterofermentative <ref name="mtf_wiki_shaner"></ref> || 1 liter starter for a 5 gallon batch of beer, 1|| Produces more lactic acid at higher temperatures and in low hop worts.020 DME sterile wort, no stir plate, no O2, starter at 90°F if possible 570-95 F Temperature Range|-7 days | [[Inland Island Brewing & Consulting|Inland Island Yeast Laboratories]] | Incubate at 90°F for 5| INISBC-7 days for greater 992 || L. delbruekii || Homofermentative || || Produces more lactic acid production. Cell count: 1.0 x 10<sup>8</sup> (100 million) cells/mL (10 billion cells at higher temperatures and 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>low hop worts. 70-95 F Temperature Range
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| [[Wyeast]] || 5223-PC || L. brevis Inland Island Brewing & Consulting|| 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 10<sup>8</sup> (100 million) cells/mL (10 billion cells in a 100 mL homebrew pouch) <ref name="wyeast_cellcounts"></ref>.|-| [[Omega Inland Island Yeast LabsLaboratories]] || OYLINISBC-605 932 || L. brevis, <span style="text-decoration: line-through;">delbrueckii</span>, and plantarum blend fermentum || Hetero/Hetero <ref name="mtf_wiki_shaner"></ref> Heterofermentative || 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 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 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-605. 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-souring-beer/ Lactobacillus 2.0 – Advanced Techniques for Fast Souring Beer. Sour Beer Blog. Matt Miller. 11/18/2015. Retrieved 11/19/2015.]</ref>.
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| [[GigaYeast]] || GB110 || L. 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>.
We recommend brewing with GB110 in one of three ways. I) “Hot Start”: Pitch GB110 to wort at 98 F with little or no hops for 48-72 hrs. Wort may be soured before kettle boil or after. If soured before kettle boil, boil with hop additions as usual. If soured after kettle boil cool wort and pitch yeast. II) “Co-Pitch”: Pitch GB110 into a primary with yeast of your choice at 68-72 F. Wort that is less than 1050 and 7 IBU will typically be very sour in 2-3 weeks. III) “Secondary”: Pitch GB110 after primary fermentation for an aged sour. Souring by this method typically requires several months. Adding simple sugars or fruit etc. will enhance souring in the secondary <ref>[http://www.gigayeast.com/fast-souring-lacto GigaYeast Webpage. Retrieved 7/22/2015.]</ref>. Sometimes referred to as GigaYeast's "Fast Acting Lacto". This strain is hop sensitive <ref name="steve_smith">[https://www.facebook.com/groups/MilkTheFunk/permalink/1068326413195572/?comment_id=1069411906420356&offset=0&total_comments=12&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Steve Smith of GigaYeast on MTF. 05/08/2015.]</ref>.
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| Lallemand || WildBrew Sour Pitch || L. 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 homofermentative || || 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 8 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: 86-104°F.
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| [[Omega Yeast Labs]] || OYL-605 || L. brevis, <span style="text-decoration: line-through;">delbrueckii</span>, and plantarum blend || 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. || 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 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 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-605. 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-souring-beer/ Lactobacillus 2.0 – Advanced Techniques for Fast Souring Beer. Sour Beer Blog. Matt Miller. 11/18/2015. Retrieved 11/19/2015.]</ref>.
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| [[RVA Yeast Labs]] || RVA 600 || L. rhamnosus GG || Homofermentative || No starter necessary per RVA || Homofermentative Lacto strain found in probiotics; sensitive to hops; does well at room temperature.
| [[SouthYeast Labs]] || Lactobacillus 2 || Unknown || Homofermentatative || || Source: Prickly pear fruit (South Carolina). Best suits strong sours, and lambic (high acidity).
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| [[Inland Island Brewing The Yeast Bay]] || Lactobacillus Blend || L. plantarum, L. brevis, and an unidentified ''Lactobacillus'' species || Heterofermentative || || The Lactobacillus Blend includes three strains: 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 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 vials) <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°F, 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& Consultingcomment_tracking=%7B%22tn%22%3A%22R%22%7D Impellitteri, Nick. Milk The Funk Facebook group. 03/17/2017.]</ref>.|Inland Island -| [[The Yeast LaboratoriesBay]] || INISBC-991 TYB282 || L. brevis || Heterofermentative || || Produces more 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 acid acidity (down to ~pH 3.16-3.18) in unhopped wort within 36 hours at a temperature of ~72-77 F. The higher temperatures the temperature (up to 90 F is what we've tested), the faster the acid production. This is a great strain for kettle souring, as it grows rather quickly and produces acidity fast with no detectable off flavors. We are about to begin some trials in low hopped wort to test out the acidification in the presence of hop compounds, though we presume there is some level of adaptation to hop wortscompounds given the environment in the beer from which we cultured the strain. Temperature: 70-95 F Temperature Range90 ºF. |- | [[Inland Island Brewing & Consulting|Inland Island Yeast LaboratoriesWhite Labs]] || INISBC-992 WLP677 || L. delbruekii delbrueckii (potentially misidentified) || Homofermentative 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> || no stir plate, room temp || Produces more Incubate at > 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 35 mL homebrew vial) <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/1212455192116026/?comment_id=1212475888780623&reply_comment_id=1212476575447221&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 higher temperatures 15 IBU <ref name="WL_datasheet" /><ref>[http://www.themadfermentationist.com/p/commercial-cultures.html "Commercial Brettanomyces, Lactobacillus, and in low hop wortsPediococcus Descriptions; Commercial Yeast Laboratories." The Mad Fermentationist blog. Michael Tonsmeire. Retrieved 12/12/2016.]</ref>. 70Generally heat tolerant, but sours faster between 100-95 F Temperature Range110°F <ref name="WL_datasheet">[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>
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| [[Inland Island Brewing & Consulting|Inland Island Yeast LaboratoriesWhite Labs]] || INISBC-932 WLP672 || L. fermentum 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" />; 80% attenuation (this may not reflect actual attenuation of wort in a real brewery; see reference <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1031115430250004/?comment_id=1031244193570461&offset=0&total_comments=33 Conversation with Michael Soo and Nick Impellitteri on the Milk The Funk Facebook Group. 3/5/2015.]</ref>). <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>.
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| [[Escarpment LaboratoriesWyeast]] || Lactobacillus Blend 5335 || L. brevis and L. plantarum buchneri || Heterofermentative <ref name="mtf_wiki_shaner"></ref> || || This blend is designed to be usable at 1 liter starter for a wide range 5 gallon batch of temperaturesbeer, and is especially suited for kettle souring/sour worting1. We recommend pre020 DME sterile wort, no stir plate, no O2, starter at 90°F if possible 5-acidifying wort to 4.7 days || Incubate at 90°F for 5 with -7 days for greater lactic acid, then pitching the Lactobacillus blend production. Cell count: 1.0 x 10<sup>8</sup> (100 million) cells/mL (10 billion cells in a CO2-purged kettle or fermentor at 32-42°C100 mL homebrew pouch) <ref name="wyeast_cellcounts">[https://drive.google.com/folderview?id=0B8CshC9nxYHdZmE4MmoyLXA2WVk&usp=sharing Wyeast Specifications 2015 Retail Products. 2015.]</ref>.
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| [[Escarpment LaboratoriesWyeast]] || Lactobacillus brevis 5223-PC || L. brevis || Heterofermentative <ref name="mtf_wiki_shaner"></ref><ref name="nick"></ref> || no stir plate, room temp is fine || This strain is moderately Heterofermentative (produces lactic acid, ethanol and CO2), more hoptolerant. 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-tolerant35°C) for 36 hours, and as such it can also be used 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 long-term 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 <10IBU beersref name="brevis_aeration">[http://www.ncbi.nlm. It also performs well in kettle souringnih.gov/pmc/articles/PMC547135/sour worting where fast Growth Response of Lactobacillus brevis to Aeration and Organic Catalysts. J. R. Stamer and clean lactic acidity is desiredB. O. Stoyla. We recommend pre-acidifying wort to 4 Appl Microbiol.Sep 1967; 15(5 with lactic acid): 1025–1030.]</ref>. The beer wort was not aerated, then pitching and the Lactobacillus blend fermenter was flushed with CO2. These methods need verification. Cell count: 1.0 x 10<sup>8</sup> (100 million) cells/mL (10 billion cells in a CO2-purged kettle or fermentor at 35-45°C100 mL homebrew pouch) <ref name="wyeast_cellcounts"></ref>.
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| [[The Yeast Bay]] || Lactobacillus Blend || L. plantarum, L. brevis, and an unidentified ''Lactobacillus'' species || Heterofermentative || || The Lactobacillus Blend includes three strains: 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 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: 70-100°F. Cell count: 50-80 million cells/mL (1.75-2.8 billion cells for 35 mL homebrew vials) <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>
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Although more experiments and probably needed, agitation is believed to be an important factor for both yeast and bacteria in general. Gentle stirring on a stir plate or orbital shaker, or frequent gentle manual agitation leads to faster growth and a higher number of organisms. Agitation keeps the microbes in solution. It also maximizes the microbes' access to nutrients and disperses waste evenly. In a non-agitated starter, the microbes are limited to the diffusion rate of nutrients, leading to a slower and more stressful growth <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1168024059892473/?comment_id=1174865305875015&reply_comment_id=1176092372418975&total_comments=1&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Conversation with Bryan of Sui Generis Blog about starters and agitation. 11/09/2015.]</ref>. If agitation is not possible for whatever reason, a successful starter can be made without agitation. Sam Aeschlimann reported good success with ''Lactobacillus'' starters that are not agitated <ref name="Sam_starter2"></ref>.
Although ''Lactobacillus'' are tolerant of oxygen and oxygen usually does not negatively affect their growth (except in the case of ''L. plantarum'', which has been shown to produce small amounts of acetic acid when exposed to oxygen and glucose is not present <ref name="Quatravaux_plantarum">[http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2672.2006.02955.x/full Examination of Lactobacillus plantarum lactate metabolism side effects in relation to the modulation of aeration parameters. S. Quatravaux, F. Remize, E. Bryckaert, D. Colavizza, J. Guzzo. 2006]</ref><ref name="microbewiki_plantarum"></ref>), it is also generally not needed (an exception to this may be ''L. brevis'', which has been shown to increase growth rates in the presence of oxygen <ref name="brevis_aeration"></ref>). Therefore, it is generally best practice to prevent aerating the starter with an airlock for ''Lactobacillus'' starters. If exposure to air occurs, and the starter does not smell like it has been contaminated by the exposure, then the starter can still be used.
* For information on mixed culture starters, see [[Mixed_Cultures#Starters_and_Other_Manufacturer_Tips|Mixed Culture Starters]].
Although 100% apple juice or 100% DME starters will "work" for ''Lactobacillus'' starters, they do not provide optimal growth conditions. [https://eurekabrewing.wordpress.com/2015/05/18/evaluate-starter-media-to-propagate-lactobacillus-sp/ Samuel Aeschlimann from Eureka Brewing Blog] ran a set of experiments that found a DME based recipe for starter wort that produces a very high cell density similar to that of MRS media, which provides optimal growth rates for ''Lactobacillus''.
The recipe for this starter wort is: '''1.040 SG (10°P) Dried Malt Extract wort with 10% apple juice + 20 grams of chalk (CaCO3) per liter + yeast nutrients'''. Regarding the use of chalk, it is the preferred buffer because it does not react with CO2 (unlike baking soda), so it won't be consumed by exposure to air due to CO2 production by the Lacto. 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]] suggests , 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:
# Add 100 grams of DME to around 900 mL of water and heat pasteurize/boil as you would normally do for a starter. This should make 1.040 SG (10°P) starter wort.
====Cell Growth====
<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 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://www.facebook.com/groups/MilkTheFunk/permalink/1031115430250004/?comment_id=1031228363572044&offset=0&total_comments=24 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>
Maximum cell densities of ''Pediococcus'' and ''Lactobacillus'' are around 1-9 billion cells/mL, depending on the available nutrients (amino acids and FAN) in the growth media <ref name="Peyer">[http://www.asbcnet.org/publications/journal/vol/2015/Pages/ASBCJ-2015-0811-01.aspx Growth Study, Metabolite Development, and Organoleptic Profile of a Malt-Based Substrate Fermented by Lactic Acid Bacteria. ​Lorenzo C. Peyer, Emanuele Zannini, Fritz Jacob, and Elke K. Arendt. 2015.]</ref><ref>[https://www.reddit.com/r/Homebrewing/comments/3qp7b7/advanced_brewers_round_table_neva_parker_white/cwh7iqq Neva Parker, Reddit thread. 10/29/2015.]</ref>. Cell growth rates concur with a drop in pH and a rise in [[Titratable_Acidity|titratable acidity]]. Brewer's wort has shown to be a nutritionally adequate growth medium for ''Lactobacillus''. Both growth and the the lowering of pH begin to stabilize around 12-48 hours (assuming the ''Lactobacillus'' does not have any yeast to compete with). Titratable acidity will also rise drastically during growth, but will also continue to rise after growth has completed. The maximum growth that a particular species or strain is capable of might be explained by its pH tolerance, and thus its ability to produce more acid. For example, ''L. plantarum'' has been shown to grow in a very low pH environment (3.37-3.0 pH, depending on strain) due to their ability to better control large pH gradients between the cytoplasma and the external environment. This has been shown in the [[Lactobacillus#Commercially_available_Lactobacillus_strains_and_their_pH_change_over_time|above data provided by Matt Humbard]], as well as this reference <ref name="Peyer"></ref>. Thomas Hübbe's masters thesis showed that a strain of ''L. brevis'' had a spike of growth after 50 hours, and then a small dip in cell count after 96 hours, at which time the cell count remained consistent for at least 528 hours <ref name="Hubbe"></ref>.
Cell growth can also be influenced by the presence of other microorganisms, such as ''Saccharomyces'' and ''Brettanomyces''. One study by Hübbe showed that ''L. brevis'' and ''L. parabrevis'' grew to the normal high cell counts when grown individually and without competition. When co-fermented with ''Brettanomyces'', the cell count of ''L. brevis'' was halved, and the growth rate of ''L. parabrevis'' was greatly diminished to about 15-20% (the pitching rate of ''Brettanomyces'' was also tested, and seemed to not have an effect on the ''Lactobacillus'' growth). When co-fermented with both ''S. cerevisiae'' and ''Brettanomyces'', the ''Lactobacillus'' growth was greatly diminished to about 2-13% of what the normal cell growth was without competition. This appears to correspond with anecdotal reports from brewers that some ''Lactobacillus'' species/strains do not compete well with yeast, especially ''S. cerevisiae'' <ref name="Hubbe"></ref>.
 
Most ''Lactobacillus'' species have a thermal death rate of ~145°F (63°C). 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).
====Effects of Oxygen====
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 ''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=1183242405037305&comment_tracking=%7B%22tn%22%3A%22R7%22%7D Conversation with Bryan of Sui Generis Blog on MTF regarding butyric acid production by Lactobacillus. 11/23/2015.]</ref>.
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 (H<sup>2</sup>0<sup>2</sup>), 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>. 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 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>. ''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 <ref name="Hubbe">[https://www.facebook.com/groups/MilkTheFunk/1407620505932826/ Effect of mixed cultures on microbiological development in Berliner Weisse (master thesis). Thomas Hübbe. 2016.]</ref>.
====Hop Tolerance====
<blockquote>
There is a fair bit of research into hop tolerance out there; its it's not a simple topic as a number of factors come into play to produce hop tolerance. To make things even more complicated, hop tolerance is an inducable inducible trait in many ''Lactobacillus'' species - meaning that a seemingly susceptible strain can become resistant by culturing in ever-increasing doses, and a seemingly resistant strain can become susceptible after a generation or four in a hop-free media.
I've been trying to generate a permanently high-alpha acid resistant lacto strain for a few months now. I've been culturing ''L. brevis '' in escalating IBU wort (starting at 10, currently at 25). Every 4th generation (1 generation = a subculture of a stationary-phase lacto culture, not as in # cell divisions) I pass it through 2 generations of an IBU-free media to try and select for strains which maintain this resistance. This seems to have worked up to ~18 IBU (update: 20-30 IBU), but past that point the resistance appears to remain inducableinducible. I'm hoping a few more generations will provide me with a permanently tolerant strain. Update: I had made a strong (~80ibu) wort that I diluted with unhopped wort. I would grow the ''Lactobacillus'' for a few passages (1 passage = grow culture to completion, then dilute ~1:100 into fresh wort to start next passage) at a set the IBU level, then passage to a wort 3 or so IBU higher. I did 50-60 generations before I got to the high IBU levels (~3 months, 1-2 days per generation). I never did anything to determine how much of that resistance was inheritable <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1421792324515644/?comment_id=1422244054470471&reply_comment_id=1422263561135187&comment_tracking=%7B%22tn%22%3A%22R6%22%7D Conversation 3 with Bryan of Sui Generis Blog on Milk The Funk regarding Lactobacillus hop tolerance. 09/30/2016.]</ref>.
There are some other options; I've purified (but didn't keep - doh) some pretty resistant strains from grain by by making plates where you half-fill a plate, on an angle, with a high-IBU wort, and then overlay that with a no-IBU wort. This gives you a gradient plate, with low-IBUs on the end where the hopped-wort layer is thinnest and high IBUs where it is thickest. Some of those strains were resistant to over 30IBU, but being early in my yeast farming days I didn't bother keeping those <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1002795743081973/?comment_id=1003625646332316&offset=0&total_comments=16&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation 1 with Bryan of Sui Generis Blog on Milk The Funk regarding Lactobacillus hop tolerance. 01/19/2015.]</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 resistance is generally due to the induced expression of "multi-drug transport" (MDT) genes, which are "pumps" that recognize the general chemical signature of membrane-disruptive compounds, and then pump them out of the cell. Other mechanisms may also be involved - a few papers have identified changes in the lipid make-up of the plasma membrane, which may increase stability. This change also occurs in response to alcohol (to improve stability), so its not clear if that particular change has anything to do with hop resistance.
Lactobacilli usually don't have these MDT genes 'on', which is why a lot of strains won't do well with hops in the first batch of beer, but over time become more and more tolerant as they increase expression of the MDT's. The overall MDT expression level, in theory, determines the maximum resistance of the bacteria. In the case of my experiments, I'm looking for mutants whose MDT's are permanently stuck 'on' for the resistant strain and 'off' for the sensitive strain <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1143165635711649/?comment_id=1155715074456705&offset=0&total_comments=50&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Conversation 2 with Bryan of Sui Generis Blog on Milk The Funk regarding Lactobacillus hop tolerance. 09/28/2015.]</ref>.
</blockquote>
 
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 on Milk THe Funk Facebook group). 1987.]</ref>.
 
Methner's data is shown below; graphs created by Benedikt Rausch <ref name="Methner" />. Y axis = pH, X axis = days.
 
<gallery>
File:Methner 7IBU.JPG|'''7 IBU'''
File:Methner 9IBU.JPG|'''9 IBU'''
File:Methner 11IBU.JPG|'''11 IBU'''
File:Methner 13IBU.JPG|'''13 IBU'''
File:Methner 18IBU.JPG|'''18 IBU'''
</gallery>
::'''L70''': ''L. coryniformis''
::'''L14, L18, L22, L29, L88, L92''': ''L. Brevis''
See also:
* [[Hops#Antimicrobial_Properties|Hops antimicrobial propertiesAntimicrobial Properties]] and [[Hops#Dry_Hopping|Dry Hopping Inhibits ''Lactobacillus'']].
* [http://www.garshol.priv.no/blog/337.html How hops prevent infection, by Lars Garshol].
* [https://www.youtube.com/watch?v=J2g5P7ZlGn4 Per Buer's Video Demonstration of how dry hopping inhibits ''Lactobacillus''.]
* [https://www.ratebeer.com/forums/lab-and-hops_289071.htm "CLevar" on Ratebeer.com data point on ''Lactobacillus'' being inhibited by hops, but not as much by iso-alpha acid hop extract.]
 
====Alcohol and Sugar Tolerance====
''Lactobacillus'' is generally tolerant of alcohol and high levels of sugar (although growth is diminished once sugar content exceeds 20% due to osmosis stressing the cell wall). In the presence of high amounts of ethanol, the alcohol tolerant strains pack their cell walls with fatty acids, which slows the fluidity of the cell membrane. The alcohol tolerance of ''Lactobacillus'' is dependent on both strain and the growth substrate, with alcohol tolerance generally higher when glucose or starch are available. In one study that looked at 31 strains of ''Lactobacillus'', all strains grew effectively at 4% ABV. All of them still grew at 10% ABV, although some strains exhibited difficulty growing effectively at 10% ABV. Growth was diminished in general at 12% ABV (and the few strains that were alcohol intolerant stopped growing), but most still achieved some growth. Eight of the strains tested were still able to exhibit significant growth at 16% ABV, and in general, most strains were able to exhibit at least small growth at 16% ABV (more so on starch and glucose versus cellobiose, lactose, or xylose). In general, the species that were less tolerant of high amounts of ethanol (10-16%) where: ''L. amylovorous'' (1 out of 4 strains was particularly intolerant), ''L. hilgardii'' (1 strain still grew at 16% ABV, but less than the others), ''L. pentosus'' (1 strain still grew on starch medium, but not on glucose above 10% ABV), and ''L. casei'' (most strains grew in most growth media, but generally less than other species). In general, the strains of ''L. brevis'' and ''L. plantarum'' were more tolerant of high ABV concentrations <ref>[https://link.springer.com/article/10.1007/BF01583633 Ethanol tolerance and carbohydrate metabolism in lactobacilli. R. Shane GoldM. M. MeagherR. HutkinsT. Conway. 1992.]</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%, 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 18-20% sugar content, 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>.
 
====Tolerance of Extreme Temperature====
Most ''Lactobacillus'' species have a thermal death rate of ~145°F (63°C). 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).
====Storage====
====Effects on Mixed Fermentation====
The presence of ''Lactobacillus'' can stall or slow yeast fermentation. This is likely a combination of low pH as well as the ability of lactic acid to change the way yeast ferments. Normally, yeast will ferment glucose first before any other sugars that are also available. The presence of lactic acid appears to change the way yeast ferments by allowing them to consume multiple types of sugars regardless of whether or not glucose is presetpresent. 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" />. Also found was an increase in [https://en.wikipedia.org/wiki/Diacetyl diacetyl] and [https://en.wikipedia.org/wiki/Acetoin acetoin] in the beers that were co-fermented with ''L. amylovorus'' and US-05 versus the beers that were kettle soured or mash soured. Both of these compounds are responsible for the buttery taste in beer. Normally, after primary fermentation the yeast reduces daicetyl to acetoin, which is then converted to butanediol, however during a co-fermentation with ''Lactobacillus'', this conversion was inhibited in this study <ref name="Peyer_2017" />. Sensorily speaking, the kettle soured beer tasted "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 ''L. amylovorus'' and US-05 was described as having an astringent aftertaste. This astringent aftertaste was speculated by the authors to be caused by LAB cell autlysis, which might have also contributed to a more complex flavor profile in the co-fermented beer <ref name="Peyer_2017" />.
== Commercially available Lactobacillus strains and their pH change over time ==
| Enterococcus faecalis <ref name="fao"></ref> || ||
|}
 
===Sugar Utilization===
''Lactobacillus'' generally prefers glucose, fructose, and maltose, and does not ferment maltotriose. Some species may prefer certain types of sugars over others. For example ''L. plantarum'' ferments glucose first, and then fructose if it is available. ''L. reuteri'' ferments maltose first, while ''L. brevis'' feeds on maltose, glucose, and fructose. Disaccharides such as sucrose and maltose enter the cells through specific types of membrane transport proteins called permeases, and are broken down into monosaccharides through phosphorolysis before they enter the normal carbohydrate metabolic pathway <ref name="peyer_review"></ref>. Peak sugar consumption without competition from yeast is typically 48 hours, and very little alcohol or CO2 is produced (around 0.10-0.30% ABV, far less than the 0.5% required for non-alcoholic drinks). Consumption of sugars occurs mainly during the 48 hour growth period, but also occurs after growth has stopped. No more than 0.5-1°P worth of sugar is consumed by ''Lactobacillus''. Rather than high residual sugar concentration being the limiting factor on growth it is thought that low pH and other metabolic byproducts weaken and finally stop the growth of ''Lactobacillus'' <ref name="Peyer"></ref>. For a chart and in depth discussion on what types of sugars are fermentable by different species of ''Lactobacillus'', as well as charts on secondary metabolites, see [http://phdinbeer.com/2015/04/13/physiology-of-flavors-in-beer-lactobacillus-species/ Matt Humbard's ''Physiology of Flavors in Beer – Lactobacillus Species'' blog article].
 
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]]), 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>.
 
====100% Lactobacillus Fermentation====
The amount of CO2 produced is very small in heterofermentative species. Lance Shaner of Omega Yeast Labs noted that although ''L. brevis'' is classified as obligatory heterofermentative, the human eye cannot detect any CO2 production in the Omega Yeast Lactobacillus blend (OYL-605). Lance still needs to test this blend to see if it produces any CO2 at all. There have been reliable reports of pure ''Lactobacillus brevis'' cultures producing a layer of bubbles on the surface of wort if roused <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1354678291227048/?comment_id=1354678411227036&reply_comment_id=1355288821165995&notif_t=group_comment_reply&notif_id=1468974761019794# Conversation with Richard Preiss on MTF regarding pure Lactobacillus fermentation. 07/19/2016.]</ref>. It is clear though that any type of ''Lactobacillus'', regardless of whether it is heterofermentative or homofermentative, cannot produce a krausen. Krausens are sometimes seen even with the use of commercially available ''Lactobacillus'' cultures and good sanitation techniques. If a krausen develops in wort when it is the only culture that is pitched, this is indicative of cross contamination of ''Saccharomyces'' or ''Brettanomyces'' in either the wort, or the ''Lactobacillus'' culture itself <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1083842231643990/?comment_id=1084646124896934&offset=0&total_comments=26&comment_tracking=%7B%22tn%22%3A%22R8%22%7D Discussion with Lance Shaner on MTF. 6/7/2015.]</ref>. In addition to this, heterolactic fermentation by ''Lactobacillus'' can only produce 10-20% of the ethanol that Saccharomyces can produce <ref name="PhysioLacto">[http://phdinbeer.com/2015/04/13/physiology-of-flavors-in-beer-lactobacillus-species/ Humbard, Matt. Physiology of Flavors in Beer – Lactobacillus Species. Retrieved 6/14/2015.]</ref>, therefore a high level of attenuation cannot be achieved by ''Lactobacillus'' and is again a sign of cross contamination by yeast.
Recent studies on lactic acid fermented malt beverages shows that ''Lactobacillus'' produces only about 0.1% ABV, producing "non-alcoholic" fermented malt beverages <ref name="Dongmo" /><ref name="Peyer" />. Elde 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):
<youtube>9a-ZpF2LDm8</youtube>
* See also [[100% Lactobacillus Fermentation]].
===Sugar Utilization and Primary/Secondary Metabolites=======Primary Metabolites====Lactic acid is the primary metabolite for ''Lactobacillus'' generally prefers glucose, fructose, as well as CO2 and maltoseethanol/acetate (acetic acid) in heterofermentative species. Acid production is at it's highest during the exponential growth phase, but continues into the stationary and does not ferment maltotriosedecline 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>. Some The amount of lactic and acetic acids produced varies from species to species may prefer certain types of sugars over others. For example , the referenced study showed that ''L. plantarum'' ferments glucose firstproduces more than twice the amount of lactic acid than ''L. brevis'', and then fructose if it is available. ''L. reuteri'' ferments maltose first, while produced slightly more lactic acid than ''L. brevis'' feeds on maltose, glucose, and fructose. Disaccharides such ''L. reuteri'' produced around twice as sucrose and maltose enter the cells through specific types of membrane transport proteins called permeasesmuch acetic acid than ''L. brevis'', and are broken down into monosaccharides through phosphorolysis before they enter the normal carbohydrate metabolic pathway <ref name="peyer_review"></ref>''L. Peak sugar consumption without competition from yeast is typically 48 hours, and plantarum'' produced very little alcohol or CO2 is produced (around 0.10-0.30% ABV, far less than the 0.5% required for non-alcoholic drinks)acetic acid. Consumption The small amount of sugars occurs mainly acetic acid produced by ''L. plantarum'' in this study was explained by oxygen exposure during sampling, while the 48 hour growth period, but also occurs after growth has stopped. No more than 0.5-1°P worth of sugar is consumed by obligate heterofermentative species (''LactobacillusL. reuteri''. Rather than high residual sugar concentration being the limiting factor on growth it is thought that low pH and other metabolic byproducts weaken and finally stop the growth of ''LactobacillusL. brevis'' ) produced acetic acid as a direct result of their heterolactic fermentation <ref name="Peyer"></ref>. For a chart and in depth discussion on what types of sugars are fermentable by different species of ''Lactobacillus'', as well as charts on secondary metabolites, see [http://phdinbeer.com/2015/04/13/physiology-of-flavors-in-beer-lactobacillus-species/ Matt Humbard's ''Physiology of Flavors in Beer – Lactobacillus Species'' blog article].
A small number of strains ====Secondary Metabolites====Both primary and secondary metabolites play a large role in the flavor and aroma profile of wort fermented with ''Lactobacillus'' can also break down polysaccharides and starches. They Secondary metabolites are compounds that are referred not directly related to as "amylolytic LAB"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. They generally belong to the species ''Lb. manihotivorans''Demain AL, ''LFang A. fermentum'', ''L2000. amylovorus'', ''L]</ref>. amylophilus'' These secondary metabolites are produced by the pathways mentioned above, ''Land 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. plantarum'' or ''L 12/29/2015. amylolyticus''</ref>. This seems Thus, different species and strains can produce a wide variety of flavors and aromas (compare this to be associated with a gene called "amyA", food grade lactic acid in which encodes for extracellular alpha-amylase activity, as well as alpha-glucosidase, neopullulanase, amylopectin phosphorylase, and maltose phosphorylasenone of these secondary metabolites exist). This activity is limited by high amounts These secondary metabolite are the result of glucose, maltose, or sucrose carbohydrate fermentation and amino acid metabolism <ref name="peyer_review"></ref>. Major secondary metabolites that
Many strains of An example from one study showed that ''LactobacillusL. plantarum'' and other lactic acid bacteria can produce tannaseproduced significantly more diacetyl, which is an enzyme that breaks down a certain class of tannins called "hydrolizable tannins" acetoin (for exampleyogurt-like flavor), tannic acid). The enzymatic breakdown of tannins provides a food source for the and acetaldehyde than ''LactobacillusL. reuteri''. In the cited study, a strain of and ''L. plantarumbrevis'' was selected out . These three compounds were associated with dairy-related notes of 47 other tannase producing "buttery", "lactic", and "yogurt" flavors identified during sensory testing <ref name="Peyer"></ref>. Some LAB as being can release these compounds through the highest producer catabolism of this enzymecitric acid, which is found in wort. Although the optimum pH for tannase Ester production is 5-8generally insignificant, although significant ester formation has been found during malolactic fermentation in red wines, it is also at least 50% active at a pH of 3-7 and a temperature of 15-30°C. Tannase ethyl acetate has been found to be produced as a product for removing haze in food products such as iced tea, wine, and beer malt based beverages <refname="peyer_review">[http://www.asbcnetsciencedirect.org/publicationscom/journalscience/volarticle/2016pii/Pages/ASBCJ-2016-4298-01.aspx Purification and Characteristics of Tannase Produced by S0924224415300625 Lactic Acid Bacteria, Lactobacillus plantarum H78as Sensory Biomodulators for Fermented Cereal-Based Beverages. Mari MatsudaLorenzo C. Peyer , Yayoi HiroseEmanuele Zannini , and Makoto KanauchiElke K. Arendt. 2016.]</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 ''L. reuteri'', and a small decrease of isovaleric acid coupled with a small increase of [https://en.wikipedia.org/wiki/Hexanoic_acid hexanoic acid] by ''L. brevis'', ''L. plantarum'', and ''L. reuteri'' (only 0.25-0.32 mg/L was found, and the flavor threshold of hexanoic acid is 5.4 mg/L <ref>[http://www.beveragedailyleffingwell.com/R-Dodorthre.htm Leffingwell & Associates website. Odor Thresholds. Retrieved 12/30/2015.]</ref>) <ref name="Peyer"></New-enzyme-aims-to-take-ref>. Heterofermentative species can also produce [[Tetrahydropyridine|tetrahydropyridines (THP)]], which is the-haze-out-cause of"mousy" off-iced-tea flavors <ref name="Costello">[http://wwwpubs.beveragedailyacs.comorg/doi/abs/R-D10.1021/Newjf020341r Mousy Off-enzymeFlavor of Wine:  Precursors and Biosynthesis of the Causative N-aimsHeterocycles 2-toEthyltetrahydropyridine, 2-takeAcetyltetrahydropyridine, and 2-theAcetyl-haze1-out-of-iced-tea"pyrroline by Lactobacillus hilgardii DSM 20176. BeveragedailyPeter J.comCostello and Paul A. Henschke. Guy Montague-James2002. 04]</04/2011ref>. Retrieved 011/09/2016.]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"></ref>. Some A few species, especially most strains of ''LactobacillusL. fermentum'' , and some strains could therefore have a positive effect on beer clarity by breaking down some haze forming tannins <ref>[https://wwwof ''L.facebookdelbrueckii subsp.com/groups/MilkTheFunk/permalink/1464383586923184/?comment_id=1465361093492100&reply_comment_id=1465496463478563&comment_tracking=%7B%22tn%22%3A%22R3%22%7D Review bulgaricus'', can produce ropiness in the form of this entry by Mike Lentz via MTF. 11/10/2016.exopolysaccharides, similar to [[Pediococcus]]<ref name="peyer_review"></ref>.
Lactic acid is the primary metabolite for ''Lactobacillus'', as well as CO2 and ethanol[http://www.sciencedirect.com/science/article/pii/acetate S0308814617302911#t0005 Dongmo et al. (acetic acid2017) in heterofermentative species. Acid production is at it's highest during the exponential growth phase] found 56 volatile flavor compounds, including various esters, alcohols, ketones, aldehydes, acids, ethers compounds, sulfur compounds, heterocyclic compounds, phenols, terpenes, lactones, but continues into the stationary and decline phasesseveral unidentified compounds. Typically just under 50% of the lactic acid Key compounds produced is L-lactic acid by ''Lactobacillus'' include acetaldehyde (more nutritionally relevant) while the slight majority is D-lactic acid thought to be a major flavor contributor to kettle soured beers <ref name="PeyerPeyer_2017"></ref>. The amount of lactic and acetic acids produced varies from species to species. For example), β-Damascenone, furaneol, the referenced study showed that ''L. plantarum'' produces more than twice the amount of lactic phenylacetic acid than ''L. brevis'', and ''L. reuteri'' produced slightly more lactic acid than ''L. brevis''. ''L. reuteri'' produced around twice as much 2-phenylethanol, 4-vinylguaiacol, sotolon, methional, vanillin, acetic acid than ''L. brevis'', nor-furaneol, guaiacol and ''Lethyl 2-methylbutanoate. plantarum'' produced very little acetic acid Acetaldehyde was the most impactful aroma compound found followed by propan-1-ol and γ-dodecalactone. The small amount of acetic acid Acetaldehyde was generally produced in much higher amounts (~23-64 µg/L) by the select strains of ''L. plantarum'' in this study was explained by oxygen exposure during sampling, while the obligate heterofermentative species (''L. reuteriamylolyticus'' and ''L. brevis'') produced acetic acid as a direct result of their heterolactic fermentation <ref name="Peyer"></ref>only 1.  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 growth of an organism, but often assist with survival <ref>[http:5-3 µg//www.ncbi.nlm.nih.gov/pubmed/11036689 The natural functions of secondary metabolites. Demain AL, Fang A. 2000.]</ref>L. These secondary metabolites are produced by the pathways mentioned aboveIn fact, 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 levels of flavors and aromas (compare this to food grade lactic acid in which none all of these secondary metabolites exist). These secondary metabolite are compounds differed significantly based on the result of carbohydrate fermentation species and amino acid metabolism <ref name="peyer_review"></ref>strain.  An example from one study showed that The selected strains of ''L. plantarumbrevis'' produced significantly more diacetylwere associated as having worse aromas that were dominated by methional (cooked potatoes), acetic acid (vinegar), acetoin and nor-furaneol (yogurtcaramel-like flavor), and acetaldehyde than ''L. reuteri'' and The ''L. brevisplantarum''. These three strains selected were identified as producing more positive aromas from compounds were associated with dairysuch as β-related notes of "buttery"damascenone (apple/fruit juice), "lactic"furaneol (strawberry), 2-phenylethanol (rose/caramel) and "yogurt" flavors identified during sensory testing <ref name="Peyer"></ref>. ethyl 2-methylbutanoate (citrus) Some LAB can release these compounds through the catabolism Small but significant amounts of citric acidlinalool and geraniol were also found, which is are normally terpenes found in wort[[Hops|hops]]. Ester production Vanillan is generally insignificant, 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 formed from ferulic acid by some ''Lactobacillus'' species as well as ''Oenococcus oeni'' <ref name="peyer_reviewDongmo">[http://www.sciencedirect.com/science/article/pii/S0924224415300625 Lactic Acid Bacteria as Sensory Biomodulators for Fermented Cereal-Based Beverages. Lorenzo C. Peyer , Emanuele Zannini , Elke K. Arendt. 2016.]</ref>. Some strains may also produce fusel alcohols and other off-flavors. For example the referenced study found an accumulation S0308814617302911 Key volatile aroma compounds of the fusel alcohol n-Porponal in the sample of ''L. reuteri'', and a small decrease of isovaleric lactic acid coupled with a small increase fermented malt based beverages – impact of [https://en.wikipedia.org/wiki/Hexanoic_acid hexanoic lactic acid] by ''Lbacteria strains. brevis'' Sorelle Nsogning Dongmo, ''L. plantarum''Bertram Sacher, and ''L. reuteri'' (only 0.25-0.32 mg/L was foundHubert Kollmannsberger, and the flavor threshold of hexanoic acid is 5.4 mg/L <ref>[http://www.leffingwell.com/odorthre.htm Leffingwell & Associates websiteThomas Becker. Odor Thresholds2017. Retrieved 12/30/2015.]</ref>) <ref name="Peyer"></ref>. Heterofermentative species can also produce [[Tetrahydropyridine|tetrahydropyridines (THP)]], which is the cause of "mousy" off-flavors <ref name="Costello">[doi:http://pubsdx.acsdoi.org/doi/abs/10.1021/jf020341r Mousy Off-Flavor of Wine:  Precursors and Biosynthesis of the Causative N-Heterocycles 2-Ethyltetrahydropyridine, 2-Acetyltetrahydropyridine, and 2-Acetyl-1-pyrroline by Lactobacillus hilgardii DSM 20176. Peter J. Costello and Paul A. Henschke. 2002.]<1016/ref>j. 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"></ref>foodchem. A few species, especially most strains of ''L2017. fermentum'', and some strains of ''L02. delrueckii subsp091. bulgaricus'', can produce ropiness in the form of exopolysaccharides, similar to [[Pediococcus]] <ref name="peyer_review"></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>.
Aging has a large impact on the aromas and flavors produced by ''Lactobacillus'' fermentation over time and is typically influenced by temperature of the environment, oxygen exposure, and the byproducts of fermentation. Generally, fermentation has a positive effect on preserving some aroma and flavor compounds. Other compounds may change, causing aroma and flavor changes. For example, one study characterized wort freshly fermented with ''L. plantarum'' as "butter" and honey", and when aged as "yogurt" and "sour". In the same study, ''L. reuteri'' was characterized as "sour" when fresh, and "honey" and "pungent" when aged. ''L. brevis'' was characterized as "soy sauce" when fresh, and "yeasty" and "cider" when aged <ref name="Peyer"></ref>.
 
Many strains of ''Lactobacillus'' and other lactic acid bacteria can produce tannase, which is an enzyme that breaks down a certain class of tannins called "hydrolizable tannins" (for example, tannic acid). The enzymatic breakdown of tannins provides a food source for the ''Lactobacillus''. In the cited study, a strain of ''L. plantarum'' was selected out of 47 other tannase producing LAB as being the highest producer of this enzyme. Although the optimum pH for tannase is 5-8, it is also at least 50% active at a pH of 3-7 and a temperature of 15-30°C. Tannase has been produced as a product for removing haze in food products such as iced tea, wine, and beer <ref>[http://www.asbcnet.org/publications/journal/vol/2016/Pages/ASBCJ-2016-4298-01.aspx Purification and Characteristics of Tannase Produced by Lactic Acid Bacteria, Lactobacillus plantarum H78. Mari Matsuda, Yayoi Hirose, and Makoto Kanauchi. 2016.]</ref><ref>[http://www.beveragedaily.com/R-D/New-enzyme-aims-to-take-the-haze-out-of-iced-tea "http://www.beveragedaily.com/R-D/New-enzyme-aims-to-take-the-haze-out-of-iced-tea". Beveragedaily.com. Guy Montague-James. 04/04/2011. Retrieved 011/09/2016.]</ref>. Some ''Lactobacillus'' strains could therefore have a positive effect on beer clarity by breaking down some haze forming tannins <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1464383586923184/?comment_id=1465361093492100&reply_comment_id=1465496463478563&comment_tracking=%7B%22tn%22%3A%22R3%22%7D Review of this entry by Mike Lentz via MTF. 11/10/2016.]</ref>.
See the [[Lactobacillus#100.25_Lactobacillus_Fermentation|Elke Arendt video presentation above]] on the referenced study, starting at ~14:45.

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