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Lactobacillus

8,924 bytes added, 15:15, 5 July 2017
added new Bootleg Biology L. plantarum blend, and alphabetized by manufacturer
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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 a wide range of temperatures, and < 117°F is especially suited for 5-7 days for greater lactic acid production. Cell count: 50-80 million cellskettle souring/mL (1sour worting.75We recommend pre-2acidifying wort to 4.8 billion cells 5 with lactic acid, then pitching the Lactobacillus blend 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 CO2-purged 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>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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| [[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 & ConsultingThe Yeast Bay]] || INISBC-991 Lactobacillus Blend || L. plantarum, L. brevis , and an unidentified ''Lactobacillus'' species || Heterofermentative || || Produces more lactic acid at higher 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 low hop wortsa 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 48-95 F Temperature Range72 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 Impellitteri, Nick. Milk The Funk Facebook group. 03/17/2017.]</ref>.|- | [[Inland Island Brewing & ConsultingWhite 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 & ConsultingWhite 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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====[[White Labs]] on WLP672====
"It is intended for secondary, so you only need to do a starter if you are doing a primary fermentation with it. DME would be the best substrate... Since its a Lacto species, you don't really want to aerate it. A slow stir-plate would be good, to keep it moving, but not much more than that." - Sarah Neel, White Labs, Sales and Customer Service (quoted with permission).
 
Since WLP672 is meant for long term aging, it is not preferred to use for kettle souring/wort souring. See also [[100%25_Lactobacillus_Fermentation#History|100% ''Lactobacillus'' fermentation]].
===General Advice===
Another thing to consider is that achieving a pH of 4 as fast as possible is advisable for preventing off-flavors from contaminating microbes <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1180630378631841/?comment_id=1181674265194119&reply_comment_id=1181715048523374&comment_tracking=%7B%22tn%22%3A%22R7%22%7D Conversation with Bryan of Sui Generis Blog on MTF regarding speed of acid production with Lacto. 11/20/2015.]</ref>. Larger pitch rates tend to achieve a lower pH faster <ref name="bryan_lacto_starters"></ref>. Therefore, unless using [[Lactobacillus#Samuel_Aeschlimann.27s_Starter_Procedures|Samuel Aeschlimann's starter procedure]], pitching 0.5-1 liters of starter for 5 gallons of wort is advisable in general. Even when using [[Lactobacillus#Samuel_Aeschlimann.27s_Starter_Procedures|Samuel Aeschlimann's starter procedure]], over-pitching ''Lactobacillus'' is not a concern (pitching an overly massive starter wort could produce undesirable flavors), so the same pitch rate should still be considered unless the brewer is confident that high growth rate has been achieved in the starter. Other factors that might affect the effectiveness of a volume based starter is the species/strain of the ''Lactobacillus'' being used, how much yeast contamination has occurred, and how old the ''Lactobacillus'' starter is. Some species/strains may require a larger volume of starter, as well as if yeast has contaminated the starter or wort (see [[Lactobacillus#100.25_Lactobacillus_Fermentation|100% Lactobacillus Fermentation]]). If a ''Lactobacillus'' culture is older than 1 month, then a fresh starter should be made. Keeping a separate Erlenmeyer flask for ''Lactobacillus'' starters can help to prevent yeast contamination <ref>Private correspondence with Richard Preiss to Dan Pixley. 11/20/2015.]</ref>, as well as using sterilization equipment such as an autoclave or pressure cooker.
Starter mediums that brewers have used include unhopped DME wort starters and apple juice starters. These tend to be adequate for many brewers. However, [https://eurekabrewing.wordpress.com/2015/05/18/evaluate-starter-media-to-propagate-lactobacillus-sp/ Samuel Aeschlimann from Eureka Brewing Blog] showed that using DME with a little bit of apple juice, chalk, and yeast nutrients provides close to optimal cell densities that match MRS media cell densities. See [[Lactobacillus#Samuel_Aeschlimann.27s_Starter_Procedures|Samuel Aeschlimann's Starter Procedures]]. Specific nutrients that will increase growth is thiamine (vitamin B1), or a combination of thiamine and riboflavin (vitamin B2). For example, it has been shown that thiamine is required in order for ''L. brevis'' to efficiently convert pyruvate into lactic acid and ethanol. The addition of these nutrients can help encourage growth <ref>[http://onlinelibrary.wiley.com/doi/10.1002/jib.385/full The influence of thiamine and riboflavin on various spoilage microorganisms commonly found in beer. Barry Hucker, Melinda Christophersen, Frank Vriesekoop. 2017.]</ref>.
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 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 and Nick Impellitteri from [[The Yeast Bay]] suggest that using the smaller amount of 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>. 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.
<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 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.]
====Storage====
* See [http://basementbrewlab.com/lab/lab-media/sla/ Rogosa SL Agar (Lactobacillus); Basement Brew Lab, by Dustin Metzger] for more information.
 
====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 preset. See [[Lactic Acid]] for more information.
== 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 maltose, and does not ferment maltotriose. Some ethanol/acetate (acetic acid) in heterofermentative species may prefer certain types of sugars over others. For example Acid production is at it''L. plantarum'' ferments glucose firsts highest during the exponential growth phase, but continues into the stationary and then fructose if it is availabledecline phases. ''Typically just under 50% of the lactic acid produced is L. reuteri'' ferments maltose first, -lactic acid (more nutritionally relevant) 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 slight majority is D-lactic acid <ref name="peyer_reviewPeyer"></ref>. Peak sugar consumption without competition from yeast is typically 48 hours, The amount of lactic and very little alcohol or CO2 is acetic acids produced (around 0varies from species to species.10-0.30% ABV For example, 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 referenced study showed that ''LactobacillusL. plantarum''. Rather produces more 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 twice the growth amount of lactic acid than ''LactobacillusL. brevis'' <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://phdinbeerL.com/2015/04/13/physiology-of-flavors-in-beer-lactobacillus-species/ Matt Humbardreuteri's 'produced slightly more lactic acid than 'Physiology of Flavors in Beer – Lactobacillus Species'' blog article]L.  A small number of strains of brevis''Lactobacillus'' can also break down polysaccharides and starches. They are referred to as "amylolytic LAB". They generally belong to the species ''LbL. manihotivoransreuteri'', produced around twice as much acetic acid than ''L. fermentumbrevis'', and ''L. amylovorusplantarum'', produced very little acetic acid. The small amount of acetic acid produced by ''L. amylophilusplantarum''in this study was explained by oxygen exposure during sampling, while the obligate heterofermentative species (''L. plantarumreuteri'' or and ''L. amylolyticusbrevis''. This seems to be associated with ) produced acetic acid as 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 direct result of glucose, maltose, or sucrose their heterolactic fermentation <ref name="peyer_reviewPeyer"></ref>.
Many strains of ''Lactobacillus'' ====Secondary Metabolites====Both primary and other lactic acid bacteria can produce tannase, which is an enzyme that breaks down secondary metabolites play a certain class of tannins called "hydrolizable tannins" (for example, tannic acid). The enzymatic breakdown large role in the flavor and aroma profile of tannins provides a food source for the wort fermented with ''Lactobacillus''. In Secondary metabolites are compounds that are not directly related to the cited study, a strain growth 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, winean organism, and beer but often assist with survival <ref>[http://www.asbcnetncbi.orgnlm.nih.gov/publicationspubmed/journal/vol/2016/Pages/ASBCJ-2016-4298-01.aspx Purification and Characteristics 11036689 The natural functions of Tannase Produced by Lactic Acid Bacteria, Lactobacillus plantarum H78secondary metabolites. Mari MatsudaDemain AL, Yayoi Hirose, and Makoto KanauchiFang A. 20162000.]</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>[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-JamesPrivate correspondence with Richard Preiss from Dan Pixley. 0412/0429/20112015. Retrieved 011/09/2016.]</ref>. Some ''Lactobacillus'' Thus, different species and strains could therefore have can produce 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 wide variety of flavors and aromas (compare this entry by Mike Lentz via MTFto food grade lactic acid in which none of these secondary metabolites exist). 11/10/2016.]These secondary metabolite are the result of carbohydrate fermentation and amino acid metabolism <ref name="peyer_review"></ref>. Major secondary metabolites that
Lactic acid is the primary metabolite for An example from one study showed that ''L. plantarum'' produced significantly more diacetyl, acetoin (yogurt-like flavor), and acetaldehyde than ''L. reuteri'' and ''LactobacillusL. brevis''. These three compounds were associated with dairy-related notes of "buttery", "lactic", as well as CO2 and ethanol"yogurt" flavors identified during sensory testing <ref name="Peyer"></acetate (acetic ref>. Some LAB can release these compounds through the catabolism of citric acid) , which is found in heterofermentative specieswort. Acid Ester production is at it's highest generally insignificant, although significant ester formation has been found during the exponential growth phasemalolactic fermentation in red wines, but continues into the stationary and decline phases. Typically just under 50% of the lactic acid ethyl acetate has been found to be produced is L-lactic acid (more nutritionally relevant) while the slight majority is D-lactic acid in malt based beverages <ref name="Peyerpeyer_review">[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>. The amount of lactic Some strains may also produce fusel alcohols and acetic acids produced varies from species to speciesother off-flavors. For example, the referenced study showed that found an accumulation of the fusel alcohol n-Porponal in the sample of ''L. plantarumreuteri'' produces more than twice the amount , and a small decrease of isovaleric acid coupled with a small increase of lactic [https://en.wikipedia.org/wiki/Hexanoic_acid hexanoic acid than ] by ''L. brevis'', and ''L. reuteriplantarum'' produced slightly more lactic acid than , and ''L. brevisreuteri''(only 0. ''L25-0. reuteri'' produced around twice as much acetic acid than ''32 mg/L. brevis''was found, and ''the flavor threshold of hexanoic acid is 5.4 mg/L<ref>[http://www.leffingwell.com/odorthre.htm Leffingwell & Associates website. Odor Thresholds. Retrieved 12/30/2015. plantarum'' produced very little acetic acid]</ref>) <ref name="Peyer"></ref>. The small amount 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 of Wine:  Precursors and Biosynthesis of acetic acid produced the Causative N-Heterocycles 2-Ethyltetrahydropyridine, 2-Acetyltetrahydropyridine, and 2-Acetyl-1-pyrroline by ''LLactobacillus hilgardii DSM 20176. Peter J. Costello and Paul A. Henschke. 2002.]</ref>. plantarum'' in this study was explained by oxygen exposure during sampling 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, while the obligate heterofermentative and valine to form fruity flavors <ref name="peyer_review"></ref>. A few species (, especially most strains of ''L. reuterifermentum'' , and some strains of ''L. brevisdelbrueckii subsp. bulgaricus'') produced acetic acid as a direct result , can produce ropiness in the form of their heterolactic fermentation exopolysaccharides, similar to [[Pediococcus]] <ref name="Peyerpeyer_review"></ref>.
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://www.ncbisciencedirect.nlm.nih.govcom/science/article/pubmedpii/11036689 The natural functions of secondary metabolitesS0308814617302911#t0005 Dongmo et al. Demain AL(2017)] found 56 volatile flavor compounds, including various esters, alcohols, ketones, aldehydes, acids, ethers compounds, sulfur compounds, heterocyclic compounds, phenols, terpenes, lactones, Fang A. 2000.]</ref>and several unidentified compounds. These secondary metabolites are Key compounds produced by the pathways mentioned above''Lactobacillus'' include acetaldehyde, β-Damascenone, furaneol, phenylacetic acid, 2-phenylethanol, 4-vinylguaiacol, sotolon, methional, vanillin, acetic acid, nor-furaneol, guaiacol and different strains probably regulate ethyl 2-methylbutanoate. Acetaldehyde was the enzymes involved in various pathways differently most impactful aroma compound found followed by propan-1-ol and produce different secondary metabolites <ref>Private correspondence with Richard Preiss from Dan Pixleyγ-dodecalactone. 12Acetaldehyde was generally produced in much higher amounts (~23-64 µg/29/2015L) by the select strains of ''L. plantarum'', while ''L. amylolyticus'' and ''L. brevis'' produced only 1.<5-3 µg/ref>L. ThusIn fact, different the levels of all of these compounds differed significantly based on the species and strain. The selected strains can produce a wide variety of flavors and ''L. brevis'' were associated as having worse aromas that were dominated by methional (compare this to food grade lactic cooked potatoes), acetic acid in which none of these secondary metabolites exist(vinegar), and nor-furaneol (caramel-like). These secondary metabolite are the result 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 carbohydrate fermentation linalool and amino geraniol were also found, which are normally terpenes found in [[Hops|hops]]. Vanillan is formed from ferulic acid metabolism by some ''Lactobacillus'' species as well as ''Oenococcus oeni'' <ref name="peyer_reviewDongmo">[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>.
An example from one 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 showed that compared volatile acids produced by a probiotic strain of ''L. plantarum'' produced significantly more diacetyl, acetoin (yogurt-like flavorNCIMB 8826)when fermented in oats, barley, malted barley, and acetaldehyde than ''Lwheat. reuteri'' In oats, there was slight increase in oleic acid and linoleic acid and ''L. brevis''a decrease when fermented in wheat, barley, or malted barley. These three In malted barley, there were small increases in flavor active compounds were associated with dairy-related notes of such as furfural ("butteryalmond"flavor), 2-ethoxyethyl acetate and isoamyl alcohol, but little to none detected when fermented in oats, "lactic"wheat, and "yogurt" flavors identified during sensory testing <ref name="Peyer"></ref>or unmalted barley. Some LAB can release these compounds through the catabolism of citric Acetic acid, which is found production was higher in barley and malted barley than it was in wortoats and wheat. Ester production is generally insignificantMany other organic acids in the oats, wheat, barley, although significant ester formation has been found and malted barley were supposedly taken up by the ''L. plantarum'' during malolactic fermentation in red wines. In barley, and ethyl acetate has been found to be produced there were trace amounts of new acids created that were not already in malt based beverages the barley itself <ref name="peyer_review">[http://www.sciencedirect.com/science/article/pii/S0924224415300625 Lactic Acid Bacteria as Sensory Biomodulators for Fermented CerealS0308814609004373 Volatile compounds produced by the probiotic strain Lactobacillus plantarum NCIMB 8826 in cereal-Based Beverages. Lorenzo C. Peyer based substrates Ivan Salmeron, Pablo Fuciños, Emanuele Zannini Dimitris Charalampopoulos, Elke KSeverino S. ArendtPandiella. 20162009.]</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 species of ''L. reuteriLactobacillus'', and a small decrease of isovaleric acid coupled with a small increase of [https://en.wikipedia.org/wiki/Hexanoic_acid hexanoic acid] by including ''L. brevislactis'', and ''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.leffingwell.com/odorthre.htm Leffingwell & Associates website. Odor Thresholds. Retrieved 12/30/2015.]</ref>) <ref name="Peyer"></ref>. Heterofermentative species can also produce [[Tetrahydropyridine|tetrahydropyridines diacetyl (THP)]], which is the cause of "mousy" off-flavors <ref name="Costello">[http://pubs.acs.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 can be reduced to acetoin and Paul A. Henschke. 2002.]</ref>. Aldehydes (2-methyl-1-propanal, 2-methyl-1-butanal, 3-methyl-1-butanalbutanediol) and their associated non-fusel alcohols (2-methyl-1-propanolas an intermediate metabolite from consuming sugar, 2-methyl-1-butanolcitrate, 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>. A few speciesHowever, especially most strains of ''L. fermentum''citrate levels are rather low in malted barley (but higher in sorghum), and some strains of ''L. delrueckii subsp. bulgaricus'', can produce ropiness diacetyl production has been observed to be very low in the form of exopolysaccharides, similar to [[Pediococcus]] barley and oat based worts <ref name="peyer_review"></ref>.
The type of grain that Aging has a large impact on the aromas and flavors produced by ''Lactobacillus'' fermentation over time and 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 typically influenced by a probiotic strain temperature of ''L. plantarum'' (NCIMB 8826) when fermented in oatsthe environment, barley, malted barleyoxygen exposure, and wheatthe byproducts of fermentation. In oatsGenerally, there was slight increase in oleic acid fermentation has a positive effect on preserving some aroma and linoleic acid and a decrease when fermented in wheat, barley, or malted barleyflavor compounds. In malted barley, there were small increases in flavor active Other compounds such as furfural ("almond" flavor)may change, 2-ethoxyethyl acetate causing aroma 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 wheatflavor changes. Many other organic acids in the oatsFor example, wheat, barley, and malted barley were supposedly taken up by the one study characterized wort freshly fermented with ''L. plantarum'' during fermentationas "butter" and honey", and when aged as "yogurt" and "sour". 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 some species of ''Lactobacillus''same study, including ''L. lactisreuteri'' was characterized as "sour" when fresh, and "honey" and "pungent" when aged. ''L. plantarumbrevis'', produce diacetyl (which can be reduced to acetoin and 2,3-butanediol) was characterized as an intermediate metabolite from consuming sugar, citrate"soy sauce" when fresh, and amino acids. However, citrate levels are rather low in malted barley (but higher in sorghum), "yeasty" and diacetyl production has been observed to be very low in barley and oat based worts "cider" when aged <ref name="peyer_reviewPeyer"></ref>.
Aging has a large impact on the aromas and flavors produced by Many strains of ''Lactobacillus'' fermentation over time and other lactic acid bacteria can produce tannase, which is typically influenced by temperature an enzyme that breaks down a certain class of the environment, oxygen exposuretannins called "hydrolizable tannins" (for example, and the byproducts of fermentationtannic acid). Generally, fermentation has The enzymatic breakdown of tannins provides 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 food source for the ''L. plantarumLactobacillus'' as "butter" and honey", and when aged as "yogurt" and "sour". In the same cited study, a strain of ''L. reuteriplantarum'' was characterized selected out of 47 other tannase producing LAB as "sour" when freshbeing 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 "honey" 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 "pungenthttp://www.beveragedaily.com/R-D/New-enzyme-aims-to-take-the-haze-out-of-iced-tea" when aged. Beveragedaily.com. Guy Montague-James. 04/04/2011. Retrieved 011/09/2016.]</ref>. Some ''L. brevisLactobacillus'' was characterized as "soy sauce" when fresh, and "yeasty" and "cider" when aged strains could therefore have a positive effect on beer clarity by breaking down some haze forming tannins <ref name>[https://www.facebook.com/groups/MilkTheFunk/permalink/1464383586923184/?comment_id=1465361093492100&reply_comment_id=1465496463478563&comment_tracking="Peyer">%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.
===External Resources===
* [https://www.microbes.info/resource-topic/lactobacillus-eubacteria-microorganisms-general-microbiology Microbes.info links to species databases and microbiology resources.]
* [https://matthumbard.wordpress.com/2015/04/13/physiology-of-flavors-in-beer-lactobacillus-species/ Physiology of Flavors in Beer – Lactobacillus Species] - Matt Humbard's overview of different species of Lactobacillus physiology, discussion on homofermentative vs heterofermentative physiology, which species can ferment different types of sugars, and secondary metabolites. Extensive data points included.
* [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.
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