Lacto Brevis vs. Delbruekii

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got my hands on White labs 672 (Brevis) 677 (Delbruekii) and split a batch (5 gallons each) - the one i have labeled as Delbruekii is cranking like no other blowing off for 2 days now. the other one is still. silent. nothing. Ive read conflicting things on these bacteria. Unless i mislabeled my carboys, Delbruekii is heterofermentive producing C02 etc. and Brevis is homofermentive producing only, or mostly, lactic acid. I will taste later this evening and PH test and report back.
 
with white labs both the brevis and delbrueckii are heterofermentative (confirmed with white labs via email) and you should see a kreusen. i did experiments with both that you can see here that confirmed this.

http://www.hommelhomebrew.com/?p=7


if you aren't seeing kreusen on the brevis then that is not a good sign. either you missed it (it can be vigorous but short lived depending on gravity), it hasn't gotten going yet or it ain't gonna get going (aka in bug heaven).

fyi, you should also see decent gravity drop with both. WL brevis should ferment out almost as much as ale yeast (depends on gravity) and WL delbrueckii should get about half way there. Of course you should see a very nice pH drop with both down into the low 3s. for me it took a few days but that was only 1 gallon with a full vial.
 
Thanks for the quick reply and info - why didn't i think to email White labs?

As of this morning the Delbruekii is still cranking (blowing off) and the Brevis is motionless. I filled both carboys to about an inch below the bottom of the neck. The Delbrueki has lost about 1/4-1/2 gallon from blow off and the Brevis volume remains as it was after pitching, so i dont think missed vigorous activity. HOWEVER, the brevis is definitively sour! i didnt have time to taste the Delbruekii or take a gravity, but i will do so tonight and post back.
 
I have a culture of brevis going and it's not showing visible signs either, but the population is definitely growing, and it's definitely getting sour. I just stepped it up so we'll see how it does. Given the number of reports with this same question, I'm guessing that brevis doesn't behave the way we'd expect.
 
Well, after 3 full days the brevis started cranking. Interesting that it had soured considerably before showing any signs of activity whatsoever. WL Brevis (and delbruekii) are certainly heterofermentive. Im going to see how low in PH i can get these, and then test gravity as well.
 
Despite the fact the Delbruekii started with a bang and continues chugging away, Its PH is 4.43 vs Brevis which only started showing signs of life 3 days later (yesterday) and is at 3.47. PH readings were taken after almost exactly 4 days from pitch (3 days 22 hours). For those wanting lots of acidity fast Brevis seems to be the way to go despite its strange behavior.
 
I've been been building up and using Brevis recently and haven't seen any real krausen, just some small bubbles at the top. It definitely dried out all my starters though. I actually recommend trying some decanted starter wort from Brevis, it's pretty good.
 
i think a lot of the pH drop rate depends on your pitch rate. wyeast recommends 35 billion cells per gallon. i was doing one gallon batches in my experiments with a single vial/pouch and that was under half the recommended pitch rate. so if you are pitching a vial into 5 gallons you are waaaaayyyyy underpitching so you will likely see very different behavior. from what i've been seeing it appears brevis does better underpitched than delbrueckii which seems to be what you are seeing as well.

my general take away has been a 1 vial/pouch into 1L starter at a minimum is a good idea for a 5 gallon batch to ensure quick souring.
 
I boiled for 15 minutes, cooled to 90ish, and pitched WL straight from the tube into 2 separate full 5 gallon carboys. I had NO hop additions. This was a "see what happens and learn" experiment - i want to see how these bacteria perform in a more ideal/preferred environment.

The Brevis gravity is currently 1.010 and the Delbruekii is 1.006 (Started at about 1.040). So, despite my dramatically low pitch rates those suckers went to work in a major way. Also the Brevis is extremely sour at this point and tastes to me quite a bit like tropical fruit while the Delbruekii is only slightly tart and has a more saison-like character. I am going to pull a half gallon of each into growlers and continue to see what happens and blend the remaining portions and add some Brett.
 
my general take away has been a 1 vial/pouch into 1L starter at a minimum is a good idea for a 5 gallon batch to ensure quick souring.

Why use a starter? I see no reason to use a starter with Lacto; it actually slows the process by introducing a second lag phase.
 
with bigger pitch it will sour faster. based on slide 22 of this preso:

http://www.homebrewersassociation.org/attachments/presentations/pdf/2012/1616-09%20A%20Perspective%20on%20Brewing%20Weisse-style%20Beer%20-%20Jess%20Caudill%20&%20Jason%20Kahler.pdf

Jess recommends 10 millions cells per ml. there are 3785 ml in a gallon so that is 37.9 billion cells per gallon. i emailed both wyeast and white labs to get cell counts for there pitches. wyeast is 10 billion per vial. white labs is ~ 2.3B per pouch. i haven't seen growth rate data for lacto so it is a total guess to say 1L starter but i know for sure that a vial isn't any where close to his recommended rate.

that said, you can see if jess' preso that even the lower pitch rate still eventually sours it just takes a few days longer which means your wort will be sitting exposed at an infection friendly pH for a lot longer.
 
Clearly pitch rate should have an influence on the behavior of both of these strains of lacto - exactly how will depend on a myriad of factors including OG, nature of wort (grain bill), temp, IBUs, and other/specific strain-related fermentation properties. What i now know is that 1 vile of WL of both strains are capable of attenuating 5 gallons of mostly base malt wort (70%p pils) in 5-7 days at about 90 degrees to the point where I can make some tasty sour beers. Notably, brevis works very quickly at producing acidity and Delbruekii works slower in this regard. Also very big differences in taste.

Of interest to me at this point is to what extent each of these strains produced ethanol vs other compounds. For those interested in sour worting (boiling after lacto does its thing) this may not matter much as the boil will presumably remove all etoh. However, as I am interested in both sour-worting and finishing with Sac and Brett keeping lacto in culture, it is going to be more difficult to estimate ethanol content given that an unknown amount of sugar was metabolized into etoh vs lactic, acetic, C02, etc. Again, there is little information available to this effect.
 
In general from what I've read, the amount of sugar that is turned into lactic acid is pretty small, so assuming that the entire drop in gravity is sugar turning to ethanol is a good assumption
 
good write up by TMF on lacto and effects on ABV calc:

http://www.themadfermentationist.com/2013/11/calculating-abv-for-sour-beers.html

key part

<the mad fermentationist>
The production of lactic acid by homofermentative strains of lactic acid bacteria utilizes sugar to make lactic acid and essentially nothing else (no CO2 is produced). This could theoretically lead to a higher FG than otherwise as these sugars would not be available for alcoholic fermentation, but it wouldn’t disrupt the calculation of ABV because these microbes don’t generate carbon dioxide as a byproduct. So our original assumption is still valid.

The heterofermentative production of lactic acid produces 1 molecule of lactic acid, plus 1 molecule each of CO2 and ethanol from each molecule of glucose. As a result you’ll still get the same gravity drop for each unit of alcohol produced. The molecule of lactic acid is incidental, similar to homofermentative lactic acid production.
</the mad fermentationist>
 
with bigger pitch it will sour faster. based on slide 22 of this preso:

http://www.homebrewersassociation.org/attachments/presentations/pdf/2012/1616-09%20A%20Perspective%20on%20Brewing%20Weisse-style%20Beer%20-%20Jess%20Caudill%20&%20Jason%20Kahler.pdf

Jess recommends 10 millions cells per ml. there are 3785 ml in a gallon so that is 37.9 billion cells per gallon. i emailed both wyeast and white labs to get cell counts for there pitches. wyeast is 10 billion per vial. white labs is ~ 2.3B per pouch. i haven't seen growth rate data for lacto so it is a total guess to say 1L starter but i know for sure that a vial isn't any where close to his recommended rate.

that said, you can see if jess' preso that even the lower pitch rate still eventually sours it just takes a few days longer which means your wort will be sitting exposed at an infection friendly pH for a lot longer.

I don't think it matters. You are saving hours, not days. If you make a starter, you have 2 lag phases, each of which could be several days. If you pitch low, you only have 1 lag phase of the same length, and a little longer to reach final PH. Once going, lacto doubles it's population in about an hour.

The referenced pitch shows this difference between 1 and 15 million cells / ml. Both are near final PH after 45 hours.

They do make the statement '1 million cells/ml is not enough for fast and safe souring', but no where do they explain why. With decent sanitation, I see no issue with a lowish pitch rate
 
I don't think it matters. You are saving hours, not days. If you make a starter, you have 2 lag phases, each of which could be several days. If you pitch low, you only have 1 lag phase of the same length, and a little longer to reach final PH. Once going, lacto doubles it's population in about an hour.

The referenced pitch shows this difference between 1 and 15 million cells / ml. Both are near final PH after 45 hours.

They do make the statement '1 million cells/ml is not enough for fast and safe souring', but no where do they explain why. With decent sanitation, I see no issue with a lowish pitch rate

A very interesting point but it feels like there are impacts of pitch rate that may be strain dependent. for example, brevis seems pretty hardy and will sour even when pitch at low rates (well below 1 million cells / ml). but based on what i'm seeing and what others have posted in seems that delbrueckii (WL677) and buchneri (WY5335) are more sensitive. or maybe its not pitch rate but something else.

maybe that is what i'll test next - test WY5335 and WL677 at three different pitch rates 1> 100K cells / ml 2> 500K cells / ml 3 > 5 million cells / ml and monitor for two weeks to see pH drop rate as well as where the pH stalls. counting lacto is a big pain vs sacc so not sure i'll get myself to do it :)

on another note: with WY5335 it is 10 billion cells / vial which is a pitch rate of 500K cells / ml for a 5 gallon batch. with WL677 it is 2.3 billion cells / vial so that would be 125K cells / ml for a 5 gallon batch so in reality the 5335 is only half the 1 million number tested so should perform fairly close to Jess' test numbers based on your doubling every hour stat.
 
There is some extremely useful information in this thread - your comments are greatly appreciated.

Hommel, your suggested experiment sounds fantastic. If you do decide to do this, adding a taste test to your timecourse numbers would be hugely informative. Given that testing cell count is labor intensive (ive never tried, but sounds like you have), perhaps rather than counting you just pitch more or less viles/pouches and trust the yeast companies viability estimates. Yes, this will be more expensive, but ill split the cost with you for the information. Others would also benefit from this information, especially those who would rather not make a starter. Soon enough (if not already), there will be LHBSs that sell lacto kits to relatively inexperienced home brewers where they brew, pitch, wait, and enjoy in a matter of weeks not months.
 
I boiled for 15 minutes, cooled to 90ish, and pitched WL straight from the tube into 2 separate full 5 gallon carboys. I had NO hop additions. This was a "see what happens and learn" experiment - i want to see how these bacteria perform in a more ideal/preferred environment.

The Brevis gravity is currently 1.010 and the Delbruekii is 1.006 (Started at about 1.040). So, despite my dramatically low pitch rates those suckers went to work in a major way. Also the Brevis is extremely sour at this point and tastes to me quite a bit like tropical fruit while the Delbruekii is only slightly tart and has a more saison-like character. I am going to pull a half gallon of each into growlers and continue to see what happens and blend the remaining portions and add some Brett.

I'm a little late to this thread, but the only explanation for your final gravities here is yeast contamination. Lactobacillus (heterofermentative or homofermentative) cannot attenuate to this degree. Even assuming a heterofermentative lactobacillus, this type of metabolism means a single glucose molecule is split into 1 molecule of lactic acid, one molecule of ethanol, and one molecule of CO2. The lacto can't direct output to ethanol production at the exclusion of lactic acid production. Practically speaking, this means that if one actually experienced 75% apparent attenuation with pure lacto, you should have in the neighborhood of 1.75% lactic acid by volume. The link to the Wyeast presentation in this thread shows that Berliners with a pH of 3.0 to 3.3 are .6-.8% lactic acid. A 1.75% lactic acid beer is probably not drinkable and would be under pH 3.0.
 
I'm a little late to this thread, but the only explanation for your final gravities here is yeast contamination. Lactobacillus (heterofermentative or homofermentative) cannot attenuate to this degree. Even assuming a heterofermentative lactobacillus, this type of metabolism means a single glucose molecule is split into 1 molecule of lactic acid, one molecule of ethanol, and one molecule of CO2. The lacto can't direct output to ethanol production at the exclusion of lactic acid production. Practically speaking, this means that if one actually experienced 75% apparent attenuation with pure lacto, you should have in the neighborhood of 1.75% lactic acid by volume. The link to the Wyeast presentation in this thread shows that Berliners with a pH of 3.0 to 3.3 are .6-.8% lactic acid. A 1.75% lactic acid beer is probably not drinkable and would be under pH 3.0.

It probably hits a threshold (feedback inhibition) and stops. Gigayeast clains 1.4% after 48 hours when pitched at 98 F and 06% when copitched with sacch.

http://www.gigayeast.com/fast-souring-lacto

Description: Lactobacillus Sp.

Tasting Notes: Pronounced Sourness. Creates a modest amount of CO2 and EtOH.

Recommended Temperature Range: 68 F to 98 F

14 days at 71 F in 1045 sweet wort, pH 5.6
Apparent Attenuation&#8211; 40%
ABV&#8212;NA
Final pH&#8211; 3.6 (100X acidification)
1.4% lactic acid W/V

48 hrs at 98 F in 1045 sweet wort, pH 5.6
Apparent Attenuation&#8211; 15%
ABV&#8211; NA
Final pH&#8211; 3.6 (100X acidification)
0.6% lactic acid W/V
 
I'm a little late to this thread, but the only explanation for your final gravities here is yeast contamination. Lactobacillus (heterofermentative or homofermentative) cannot attenuate to this degree. Even assuming a heterofermentative lactobacillus, this type of metabolism means a single glucose molecule is split into 1 molecule of lactic acid, one molecule of ethanol, and one molecule of CO2. The lacto can't direct output to ethanol production at the exclusion of lactic acid production. Practically speaking, this means that if one actually experienced 75% apparent attenuation with pure lacto, you should have in the neighborhood of 1.75% lactic acid by volume. The link to the Wyeast presentation in this thread shows that Berliners with a pH of 3.0 to 3.3 are .6-.8% lactic acid. A 1.75% lactic acid beer is probably not drinkable and would be under pH 3.0.

that is definitely not my experience. i did a brevis (WL672) experiment that started at 1.031 and ended here:

Day 10
1> gravity 1.012 pH 3.09 very sour. clean. dry. 9/10 on sour scale.

i then bottle conditioned and it ended up being a really nice, sour but certainly not unpleasant berliner.

my write up is here:
http://www.hommelhomebrew.com/?p=7

I had a similar experience with WL677 although it didn't ferment out as much.

so your equation may be correct but reality plays out differently.
 
that is definitely not my experience. i did a brevis (WL672) experiment that started at 1.031 and ended here:

Day 10
1> gravity 1.012 pH 3.09 very sour. clean. dry. 9/10 on sour scale.

i then bottle conditioned and it ended up being a really nice, sour but certainly not unpleasant berliner.

my write up is here:
http://www.hommelhomebrew.com/?p=7

I had a similar experience with WL677 although it didn't ferment out as much.

so your equation may be correct but reality plays out differently.

I think the most logical explanation is that there was yeast present in the fermentation. Any chance you have any left? I can look under the scope at a sample and see if there is any yeast in there if you want (assuming you didn't add any yeast to bottle condition).
 
Those Gigayeast numbers don't make much sense either. I just took 1.040 wort with a starting pH of 5.45 and added lactic acid to a final concentration of 1%. The pH ended up at 2.9. Needless to say, it tasted extremely sour -- despite the significant sweetness in the wort. I bumped it up to a final concentration of 1.75% and it came in at pH 2.73. In any event, as I said earlier, the metabolic pathways of lactobacillus are such that 75% attenuation of a 1.040 wort would result in (at a minimum) 1.75% lactic acid -- which would result in a pH in the neighborhood of 2.7. Again, attenuation to that degree cannot be accomplished by Lactobacillus alone.
 
Those Gigayeast numbers don't make much sense either. I just took 1.040 wort with a starting pH of 5.45 and added lactic acid to a final concentration of 1%. The pH ended up at 2.9. Needless to say, it tasted extremely sour -- despite the significant sweetness in the wort. I bumped it up to a final concentration of 1.75% and it came in at pH 2.73. In any event, as I said earlier, the metabolic pathways of lactobacillus are such that 75% attenuation of a 1.040 wort would result in (at a minimum) 1.75% lactic acid -- which would result in a pH in the neighborhood of 2.7. Again, attenuation to that degree cannot be accomplished by Lactobacillus alone.

You added it yourself. You didn't have any type of feedback inhibition as I proposed might exist to stop from your 1.75% measurement. I'm not arguing that much lactic acid won't drop the pH so far but I'm saying it is possible that lactic acid may stop lactobacillus from making more.
 
Oddly enough I just pitched the Gigayeast for 48 hours and kept it above 80F (pitched at 100, wrapped in zero degree sleeping bag) for 48 hours and saw no signs of fermentation and measure no change in Gravity and the wort was a pH drop of 0.5. I probably should have let it go another 24 hours but I set my test up for 48 hours not 72.
 
DurtyChemist,

Is there any literature (or experience) to suggest that some or any strains of lacto possess feedback inhibition mechanisms that might possibly change metabolic processes as you suggest? This is very intriguing. I very much doubt that there was yeast contamination in these batches although i suppose it is a possibility. Also, I just went back to my notes and realized that i didnt take into account that the wort was 90 degrees when i took the gravity. so numbers can be bumped up by a marginal .004 - still quite attenuative lacto.

I ran out of time for this project and didnt want the beer to go to waste so i blended the two strains to beat back the crazy acidity that the brevis produced. the blended portion was amazing. still quite tart, but very tropical and crisp even with a gravity at that point of about 1.012 once cooled to about 60.

For the Gigayeast comparison (although we may be getting off 'topic'), this must be a homofermentive product right? how was the taste?
 
DurtyChemist,

Is there any literature (or experience) to suggest that some or any strains of lacto possess feedback inhibition mechanisms that might possibly change metabolic processes as you suggest? This is very intriguing. I very much doubt that there was yeast contamination in these batches although i suppose it is a possibility. Also, I just went back to my notes and realized that i didnt take into account that the wort was 90 degrees when i took the gravity. so numbers can be bumped up by a marginal .004 - still quite attenuative lacto.

I ran out of time for this project and didnt want the beer to go to waste so i blended the two strains to beat back the crazy acidity that the brevis produced. the blended portion was amazing. still quite tart, but very tropical and crisp even with a gravity at that point of about 1.012 once cooled to about 60.

For the Gigayeast comparison (although we may be getting off 'topic'), this must be a homofermentive product right? how was the taste?
I'd have to research it. I'm saying it is possible. Ya know?
I would have to go through more research papers I don't have access to anymore to see if such a thing is even being studied. I would believe it does since 48 hours under controlled temperatures don't show it reaching the 1.75% it would based on a linear calculation. I'm hypothesizing the acidity stops lactobacillus from leaking more lactic acid otherwise the pH will drop too low and kill the enzyme. No enzyme wants to make an environment detrimental to overall life to the point of termination unless you're cancer.
 
Finding directly relevant academic research about Lactobacillus metabolism in wort proved rather difficult. What I did find was a paper where the authors engineered a low-pH tolerant Lactobacillus delbrueckii using random mutagenesis. The paper mentioned a couple of nuggets that I think are relevant to their use in brewing. Apparently Lactobacillus reproduces until the pH hits about 3.8 (the pKa of lactic acid). At that point, growth ceases, and the population continues to produce lactic acid while dying at a certain rate as the pH continues to drop.

I realize I added lactic acid to the wort. The reason for that experiment was to determine what pH wort would be at with 1% and 1.75% lactic acid in order to try to make sense out of the Gigayeast numbers. The pH values I obtained were much lower than the Gigayeast numbers.

I wouldn't be surprised if there's some sort of feedback inhibition as lactic acid levels increase. However, at the point the cells could no longer make lactic acid (for whatever reason), sugars would stop being consumed. Lactobacillus must produce lactic acid in order to regenerate the NAD consumed during the breakdown of sugar. Without a replenished NAD pool, metabolism would screech to a halt. In other words, Lactobacillus metabolism produces lactic acid by necessity. If you're seeing a drop in gravity without lactic acid production, it's happening because of some other organism. Most likely yeast.
 
Finding directly relevant academic research about Lactobacillus metabolism in wort proved rather difficult. What I did find was a paper where the authors engineered a low-pH tolerant Lactobacillus delbrueckii using random mutagenesis. The paper mentioned a couple of nuggets that I think are relevant to their use in brewing. Apparently Lactobacillus reproduces until the pH hits about 3.8 (the pKa of lactic acid). At that point, growth ceases, and the population continues to produce lactic acid while dying at a certain rate as the pH continues to drop.

I realize I added lactic acid to the wort. The reason for that experiment was to determine what pH wort would be at with 1% and 1.75% lactic acid in order to try to make sense out of the Gigayeast numbers. The pH values I obtained were much lower than the Gigayeast numbers.

I wouldn't be surprised if there's some sort of feedback inhibition as lactic acid levels increase. However, at the point the cells could no longer make lactic acid (for whatever reason), sugars would stop being consumed. Lactobacillus must produce lactic acid in order to regenerate the NAD consumed during the breakdown of sugar. Without a replenished NAD pool, metabolism would screech to a halt. In other words, Lactobacillus metabolism produces lactic acid by necessity. If you're seeing a drop in gravity without lactic acid production, it's happening because of some other organism. Most likely yeast.

I had a similar experience finding academic research. My friend is a microbiologist at the local university and I asked him to look up any papers that talked about lacto growth rates and all he came up with on 50 year old paper that wasn't particularly helpful and a paper that showed growth rates for different strains but in an ideal growth environment that is nothing like what you would have with a typical starter setup so not super helpful other than showing the max growth rate that you will never come close to in a homebrewing style starter.

what you found is very interesting. with yeast you get growth rates based on available sugar and how it is agitated so yeast can get at the sugar. with lacto it sounds like it is not just sugar dependent but also pH dependent. so, if i'm reading your post correctly, you couldn't just put a small amount of lacto in a lot of sugar and get .4 cells per gram (non-agitated) or 1.4 cells per gram (agitated) like with yeast but you would have to have enough lacto present in that amount of sugar so it can replicate to the count you want before getting down to a 3.8 pH. on the other hand, maybe you don't need as much since you aren't worried about the pitch rate vs flavor profile like with yeast but you still need enough to keep generating acid in a low pH, unfriendly environment where the kill rate is high. That makes it a bit more tricky to calculate both lacto starters as well as pitch rates.

Also, my guess is different strains behave differently so with brevis maybe you get growth and continue to generate acid to a lower pH than other strains. Or not :)

The more you learn, the more you realize how much more you have to learn.
 
I'm a little late to this thread, but the only explanation for your final gravities here is yeast contamination. Lactobacillus (heterofermentative or homofermentative) cannot attenuate to this degree. Even assuming a heterofermentative lactobacillus, this type of metabolism means a single glucose molecule is split into 1 molecule of lactic acid, one molecule of ethanol, and one molecule of CO2. The lacto can't direct output to ethanol production at the exclusion of lactic acid production. Practically speaking, this means that if one actually experienced 75% apparent attenuation with pure lacto, you should have in the neighborhood of 1.75% lactic acid by volume. The link to the Wyeast presentation in this thread shows that Berliners with a pH of 3.0 to 3.3 are .6-.8% lactic acid. A 1.75% lactic acid beer is probably not drinkable and would be under pH 3.0.

You are making some assumptions here that may or may not be correct. You can't (necessarily) assume there will be a 1:1 ratio of EtOH/Lactic acid produced, as fermentation conditions and strain will likely influence that ratio (and feedback inhibition as another noted). For example, the Bruery's Hottenroth is essentially a 100% Lactobacillus fermentation (although there is a small amount of brettanomyces in their, but they contend that it comprises a very small proportion of the microbes.) WLP677 claims 75-85% attenuation. I've never fermented it alone, so I can't comment on that with direct experience.

@oldsock did a 100% lacto experiment awhile back, but it doesn't look like he noted a FG. Maybe he can weigh in here?
 
You are making some assumptions here that may or may not be correct. You can't (necessarily) assume there will be a 1:1 ratio of EtOH/Lactic acid produced, as fermentation conditions and strain will likely influence that ratio (and feedback inhibition as another noted). For example, the Bruery's Hottenroth is essentially a 100% Lactobacillus fermentation (although there is a small amount of brettanomyces in their, but they contend that it comprises a very small proportion of the microbes.) WLP677 claims 75-85% attenuation. I've never fermented it alone, so I can't comment on that with direct experience.

@oldsock did a 100% lacto experiment awhile back, but it doesn't look like he noted a FG. Maybe he can weigh in here?

I noted 1.008 after 6 weeks down in the comments. Doubt it ended up much lower.

Haven't found any great sources on what determines lactic acid production in heterofermentative strains. Anecdotally, hops seem to reduce acid production even if they aren't enough to stop fermentation.
 
with lacto it sounds like it is not just sugar dependent but also pH dependent. so, if i'm reading your post correctly, you couldn't just put a small amount of lacto in a lot of sugar and get .4 cells per gram (non-agitated) or 1.4 cells per gram (agitated) like with yeast but you would have to have enough lacto present in that amount of sugar so it can replicate to the count you want before getting down to a 3.8 pH. on the other hand, maybe you don't need as much since you aren't worried about the pitch rate vs flavor profile like with yeast but you still need enough to keep generating acid in a low pH, unfriendly environment where the kill rate is high. That makes it a bit more tricky to calculate both lacto starters as well as pitch rates.

Also, my guess is different strains behave differently so with brevis maybe you get growth and continue to generate acid to a lower pH than other strains. Or not :)

The more you learn, the more you realize how much more you have to learn.

From what I had read, I didn't think starter size, or even a starter were important, and may even be detrimental to the process, but from what you say, I might have to re-think my position on pitch rates. Got to do some more research.
 
I pitched L. Brevis in my 1.056 Saison wort (3IBU) @100*F and has been violent with activity since. It has been three days, tonight I will pitch my 1 liter starter(WL568).
 
So after pulling a sample I have no doubts that L. Brevis could 100% ferment this brew. After three days it is exceptionally clean, tart but not super sour. Amazingly that 3 IBU of Saaz plays out nicely. I could drink this as is all day.
 
So after pulling a sample I have no doubts that L. Brevis could 100% ferment this brew. After three days it is exceptionally clean, tart but not super sour. Amazingly that 3 IBU of Saaz plays out nicely. I could drink this as is all day.

It's good that you ended up with a product you like, but you had a yeast infection. L. brevis does not create a krausen and it is not capable of complete attenuation of wort.

http://www.milkthefunk.com/wiki/Lactobacillus#100.25_Lactobacillus_Fermentation
 
As for attenuation, that is why I made/pitched a 1 liter starter of WLP568 Belgian yeast blend after those 3days.
 
As for attenuation, that is why I made/pitched a 1 liter starter of WLP568 Belgian yeast blend after those 3days.

I guess I'm unclear what you mean by the L. brevis can 100% ferment the brew and that it was violent with activity. Even heterofermentative Lacto like brevis produce essentially invisible quantities of CO2.
 
It seems there is still some disagreement related to the activity of lacto - particularly its ability to attenuate wort and produce large volumes of C02. In my hands, both the strains referenced in this post appeared to be high attenuating and heterofermentive - not what i was expecting based on a limited amount of research. However, this experiment was not designed to test this hypothesis, but rather to compare strain profiles (specifically flavor and acidity without interactions with hops). Basically, i just wanted to make acid beer to blend with and thought i might as well test 2 strains with (supposedly) mechanisms of actions (homo vs heterofermentive).

There is increasing evidence from this post and elsewhere (see milk the funk wiki) that some commercial pitches of lacto have sac and/or other organisms present. This would certainly explain some of the reported behavior of the strains in this post by myself and others. Even very small amounts of other organisms - perhaps not easily detectable under a microscope - could have the ability to reproduce, especially under conditions such as those i used (high temp/lots of food).

to test this hypothesis is not trivial, at least i cannot think of a very good way, but i am not a microbiologist. Perhaps someone can weigh in on this? My initial thought is to take several samples from the pitch in a sterile environment after sanitizing packaging and then again after the same samples post fermentation.

Any suggestions would be appreciated.

Regardless of the outcome, both these strains produce tasty beer and i highly recommend them as a way to quickly produce acidity (at least in the absence of hops).

IMG_5371.jpg
 

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