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! Name !! Mfg# !! Taxonomy !! CO2 Producer (Het/Hom) !! Starter Note !! Fermentation/Other Notes

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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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| [[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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| [[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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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''.

# 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>

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.

</blockquote>

See also:

* [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''.]

| Enterococcus faecalis <ref name="fao"></ref> || ||

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====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.

<youtube>9a-ZpF2LDm8</youtube>

* See also [[100% Lactobacillus Fermentation]].

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>.

See the [[Lactobacillus#100.25_Lactobacillus_Fermentation|Elke Arendt video presentation above]] on the referenced study, starting at ~14:45.