Significant gravity drop with Lacto??

Hey guys, just to give a little background, I have been experimenting with sour mashing/kettle souring lately with both lacto brevis and del. I make a starter on a stir plate as I normally would with any other yeast and then decant/pitch into the mash or kettle. Each and every time I have done this, I have experienced a significant drop in gravity that throws me off entirely. I have read somewhere that lactic acid is dense and will throw off readings, but take my last kettle sour for example. I mashed/sparged as usual and wound up with a preboil gravity of 1.047. This would have given me an OG of 1.055-1.056 with my current setup after a 90 minute boil. I soured the wort in the kettle from Friday until Monday morning (today) and went ahead with my brew. I boiled the wort for 15 minutes before adding the lacto and then boiled for 75 minutes today. When I took my gravity reading, it was at 1.016?! I just cant seem to understand how my readings can be so off, when I would assume this isn't the case with most anyone else. Otherwise, how would you be able to tell the abv/ibus of these sorts of beers? AND, if there is such a significant amount of alcohol produced during that kettle souring period, aren't I losing it all due to the 75 minute boil before finally adding the brett/sacch? Just looking for some insight here as I continue my journey into the sour brewing world. ANY HELP would be much appreciated!!!

(By the way, the beers taste great! just trying to get a handle on things)

These must be white labs vials... They have been having issues with their lacto being contaminated with yeast. Lacto can create slight amounts of alcohol, but anything that attenuates more than .002-.003 is due to yeast. I would suggest trying a lacto culture from one of the smaller labs (omega oyl-605 is great!) to see if it solves your problems. And you're correct, you're boiling off all the ethanol in your long boil.

what agate said... likely due to yeast contamination.

Damn! Well thanks for your input guys, dont you think thats sort of messed up on their part to be selling contaminated vials? Now what do you think I should do with this fresh batch of basically non-alcoholic citra sour beer? I put a lot of work into it and wont be happy about dumping it.

If it tastes good, drink it up! I got bit by the attenuation bug on a kettle sour, and added cane sugar to replace what boiled off during the boil. Sample size of one, but it worked fine. This was with a Berliner weisse, so it wasn't much sugar.

i don't agree that this is likely a contamination issue. possible but unlikely. gravity drop with lacto is totally normal if the strain is heterofermentative. brevis is quite potent although i saw big differences between wyeast and white labs. i did a bunch of tests which you can see here where i track the gravity drop for different strains/sources:

http://www.hommelhomebrew.com/?p=44
http://www.hommelhomebrew.com/?p=7
http://www.hommelhomebrew.com/?p=129

Agate said:

http://www.milkthefunk.com/wiki/100%_Lactobacillus_Fermentation

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super interesting article. in looking at my data again the only two that fermented out were the two WL strains. man, i have a hard time believing that WL is selling contaminated lacto but it seems hard to believe otherwise based on this data. That Omega Yeast Labs L. plantarum may have to be in my next experiment. Looks very promising. Or I guess they only sell it as part of the OYL-605 blend?

You can actually get that strain as a probiotic - Swanson's sells it, and you can get it on amazon. I've used it a number of times, and it works great!

Agate said:

These must be white labs vials... They have been having issues with their lacto being contaminated with yeast. Lacto can create slight amounts of alcohol, but anything that attenuates more than .002-.003 is due to yeast. I would suggest trying a lacto culture from one of the smaller labs (omega oyl-605 is great!) to see if it solves your problems. And you're correct, you're boiling off all the ethanol in your long boil.

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Hetero-fermentative Lacto can take the gravity down a lot more than a few points. I've done it with probiotics - no yeast anywhere around.

Calder said:

Hetero-fermentative Lacto can take the gravity down a lot more than a few points. I've done it with probiotics - no yeast anywhere around.

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Do you have a source for this? I suspect that yeast contamination is a lot more common than most expect. If you haven't already, please take a look at the link I posted above on 100% lacto fermentations.

Just as a sanity check, it takes about 30 ml 88% lactic acid to drop 5g of my water to pH 3.2, or about 26.4 ml 100% lactic acid. Assuming a heterofermentative lacto makes equal amount of lactic acid and ethanol, that would be the equivalent of about 0.14% ABV. That's about equivalent to a gravity drop of 0.001-0.002.

See:
https://www.homebrewtalk.com/showthread.php?t=538153

FYI the author of that thread (and source of the wiki article earlier in this thread) is from Omega Yeast Labs. He built up a lot of cred by breaking the news that White Labs Brett Trois was not actually brett. I've seen elsewhere his theoretical analysis of the chemistry involved and that basically lacto has to produce a certain amount of acid in order to produce a certain amount of alcohol, chemically speaking. If lacto were to ferment more than a few gravity points it would have chemically needed to create so much lactic acid that it would have killed itself and created an insanely sour beer (< 3.0 pH). In other words, not possible theoretically, with a study to back it up.

D-train, in my last kettle sour the pH got down to 2.75-2.8 and fermented from 1.047 to 1.015

Agate said:

Do you have a source for this? I suspect that yeast contamination is a lot more common than most expect. If you haven't already, please take a look at the link I posted above on 100% lacto fermentations.

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Personal experience using a lacto source that had no possibility of yeast contamination (probiotics) went from 1.036 to about 1.012 (do not have specific numbers on hand right now).

Calder, what was the brand of probiotic? I still suspect yeast contamination, but I'm interested in trying it first-hand.

Yeast contamination does not necessarily have to come from your culture. It could come from sanitation and wort handling practices.

So I wanted to post this here before starting another thread just to see what you guys think. I have another starter of the lacto brevis going on the stir plate and am trying to plan my approach with this bacteria now knowing that it is contaminated with yeast. I would like to brew a very similar beer with a nice citra hoppiness, but am not sure how to sour the beer since I obviously cant boil after. I was thinking of brewing a low ibu (5-10) wheat beer and letting the lacto sour the wort in the fermenter for 3 days at maybe 80-90 degrees before adding a clean yeast. Then a nice heavy dose of citra dry hops to achieve the hoppy flavors I'm looking for? What do you guys think?

Calder said:

Personal experience using a lacto source that had no possibility of yeast contamination (probiotics) went from 1.036 to about 1.012 (do not have specific numbers on hand right now).

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Unless you're working in a completely sterile environment with all sterile equipment, there is, in fact, a very real possibility of yeast contamination. From all the structured experiments I've seen by actual scientists in places like the Milk the Funk group, it is unlikely that any Lacto will drop the gravity by that much.

http://www.milkthefunk.com/wiki/100%_Lactobacillus_Fermentation

Bisco_Ben said:

So I wanted to post this here before starting another thread just to see what you guys think. I have another starter of the lacto brevis going on the stir plate and am trying to plan my approach with this bacteria now knowing that it is contaminated with yeast. I would like to brew a very similar beer with a nice citra hoppiness, but am not sure how to sour the beer since I obviously cant boil after. I was thinking of brewing a low ibu (5-10) wheat beer and letting the lacto sour the wort in the fermenter for 3 days at maybe 80-90 degrees before adding a clean yeast. Then a nice heavy dose of citra dry hops to achieve the hoppy flavors I'm looking for? What do you guys think?

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I think that's a good idea, citra is a great dry hop for a sour beer.

The first time I got bit with the contaminated lacto bug, I pasteurized at 160°F for something like 20 minutes. Ethanol doesn't boil until 173F-ish, so as long as you keep the liquid temperature below this, you shouldn't evaporate too much. Lacto will die at 160°F, though. This would be a great temperature for a citra whirlpool addition.

Bisco_Ben said:

So I wanted to post this here before starting another thread just to see what you guys think. I have another starter of the lacto brevis going on the stir plate and am trying to plan my approach with this bacteria now knowing that it is contaminated with yeast. I would like to brew a very similar beer with a nice citra hoppiness, but am not sure how to sour the beer since I obviously cant boil after. I was thinking of brewing a low ibu (5-10) wheat beer and letting the lacto sour the wort in the fermenter for 3 days at maybe 80-90 degrees before adding a clean yeast. Then a nice heavy dose of citra dry hops to achieve the hoppy flavors I'm looking for? What do you guys think?

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i've done this with a BW but with a probiotic that didn't lower the gravity and i boiled once it got down to pH 3.2 for 10 mins then did a big (1 oz per gallon) flame out addition. it was centennial hops and i really liked the citrusy and sour combo. citra should be great.

on the boiling note, it is really hard to gauge how much of the alcohol will actually boil off. not saying i would change your process but maybe you'll find it interesting. see here:

http://www.todayifoundout.com/index.php/2011/11/alcohol-doesnt-really-cook-out-of-food-in-most-cases/

Soo I went ahead with my plan to boil for 90 mins, add lacto and kettle sour for 48 hours then raise to 165 for 30 minutes while steeping 2oz of citra hops. When i took my pH reading before the steep though, it was 2.8!!! I dont know if my meter is off or what, but wow! I rehydrated some us-05 and pitched at 70 degrees but am worried that it may never fully ferment at such a low pH. What do you guys think will happen and what should I do from here? Any insight would be great!

first, confirm your 2.8 reading.

if it holds, i would dilute with some clean wort to bring pH back up. or ferment with brett (use many strains, in hopes that at least one will be ok with 2.8).

Yeah, I'd be really suspicious of that pH reading. That would be very abnormal, and I would think borderline undrinkable if it manages to ferment.

Bisco_Ben said:

Soo I went ahead with my plan to boil for 90 mins, add lacto and kettle sour for 48 hours then raise to 165 for 30 minutes while steeping 2oz of citra hops. When i took my pH reading before the steep though, it was 2.8!!! I dont know if my meter is off or what, but wow! I rehydrated some us-05 and pitched at 70 degrees but am worried that it may never fully ferment at such a low pH. What do you guys think will happen and what should I do from here? Any insight would be great!

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i don't think us-05 will do anything at that ph level but i'd agree that i doubt you are actually at 2.8. i haven't seen lacto go much below 3.1 all by itself. even more ph tolerant ale strains like german ale are finicky below 3.5. i have had very good luck at low ph with wine yeast. my go to is lavlin ec-1118. wine must is naturally much lower in ph than wort so wine yeast is not only ok at low ph but prefers low ph. brett will likely work but you will obvious get a brett flavor profile. ec-1118 is quite neutral and the main issue is it may overly dry out your beer although with berliner weisses i haven't had an issue but they are also highly carbonated so that may offset.

Hommel said:

ec-1118 is quite neutral and the main issue is it may overly dry out your beer

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ec-1118 will not dry out a beer, as it is unable to ferment maltotriose. it can only ferment simple sugars.

Bisco_Ben said:

Soo I went ahead with my plan to boil for 90 mins, add lacto and kettle sour for 48 hours then raise to 165 for 30 minutes while steeping 2oz of citra hops. When i took my pH reading before the steep though, it was 2.8!!! I dont know if my meter is off or what, but wow! I rehydrated some us-05 and pitched at 70 degrees but am worried that it may never fully ferment at such a low pH. What do you guys think will happen and what should I do from here? Any insight would be great!

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I just did this to a gose. Hit 3.38 within 12 hours and 3.06 within 24 hours. You gotta remember pH meters are temperature sensitive as well, so it's likely your pH is a little bit higher. Mine settled out around 3.37. Still very tart, but my sacc starter had no problems fermenting.

White Labs lacto cultures are notorious for being contaminated with yeast. It's happened in my brewery twice (both with Brevis, different vials/brews several months apart). Now we plate out the vials if we get any cultures from WLP.
In fact, at CBC last year, we sought out Chris White and asked him about this, and he admitted they've had issues - he added that was one of the big reasons why they are switching over to the pouches.

I just did a kettle sour with the omega lacto blend and wanted to report back the results since it was mentioned a few times in the thread. the wort is 1.032 berlinner (2/3 pilsner, 1/3 white wheat). no hops. i got one pouch of omega's lacto blend (oyl-605) online since my local doesn't get it. it had a september 2015 date so it was 3 months old as of pitching. i cooled the wort to 85F and just pitched the pouch - no starter. wort was 5.4 at the time of pitching. i have an electric kettle so i just set my PID to 85F and let it sit. i put the lid on on but did not purge or seal it since it was a pure inoculation (ie not grain). the next day i checked it at noon which was 24 hrs and it was down to 3.20. whoa! i had to wait to boil another 4 hours. i pulled a sample right before boiling and it was 3.15 and a gravity of 1.032. so 28 hours, no starter and super sour and clean with no gravity drop. i tasted the sample and it was worty but no off flavors and nice and tart in the background. once the sugar gets fermented out it should tighten up the jowls nicely. of all the lacto strains i've tested this omega blend is the most aggressive i've seen. since the blend is plantarum and brevis (both heterofermentative) that pretty much convinces me that heterofermentative strains that are pure should not significantly reduce your gravity. Lance Shaner of Omega is my new hero.

Hommel said:

I just did a kettle sour with the omega lacto blend and wanted to report back the results since it was mentioned a few times in the thread. the wort is 1.032 berlinner (2/3 pilsner, 1/3 white wheat). no hops. i got one pouch of omega's lacto blend (oyl-605) online since my local doesn't get it. it had a september 2015 date so it was 3 months old as of pitching. i cooled the wort to 85F and just pitched the pouch - no starter. wort was 5.4 at the time of pitching. i have an electric kettle so i just set my PID to 85F and let it sit. i put the lid on on but did not purge or seal it since it was a pure inoculation (ie not grain). the next day i checked it at noon which was 24 hrs and it was down to 3.20. whoa! i had to wait to boil another 4 hours. i pulled a sample right before boiling and it was 3.15 and a gravity of 1.032. so 28 hours, no starter and super sour and clean with no gravity drop. i tasted the sample and it was worty but no off flavors and nice and tart in the background. once the sugar gets fermented out it should tighten up the jowls nicely. of all the lacto strains i've tested this omega blend is the most aggressive i've seen. since the blend is plantarum and brevis (both heterofermentative) that pretty much convinces me that heterofermentative strains that are pure should not significantly reduce your gravity. Lance Shaner of Omega is my new hero.

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Awesome! I'm glad it worked out for you - between omega and Swanson lacto-p, these are now my go-to strains for quick sours. And this is the reason I have about 25 gallons of BW and gose bottled in my basement. They're just so quick and easy to make with this blend!

Agate said:

Awesome! I'm glad it worked out for you - between omega and Swanson lacto-p, these are now my go-to strains for quick sours. And this is the reason I have about 25 gallons of BW and gose bottled in my basement. They're just so quick and easy to make with this blend!

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is this the right swanson's?

http://www.swansonvitamins.com/swanson-probiotics-l-plantarum-inner-bowel-support-30-veg-drcaps

how do you use? do you open the capsule? how many capsules per gallon? do you go straight into kettle or do you do a starter? how is the swanson's vs the omega blend? i like the omega blend but the swanson's would be a lot easier to get and much cheaper. have you had any contamination issues with the swanson's? sorry for all the questions sour minds want to know!

That would be the one!

I use about 3 capsules in a 1-liter starter, and at that point I treat it just like the omega blend. At first I was cutting the capsules open and pouring in the contents, but I got worried about contaminating it and started just dropping the whole capsules in the starter.

I know of people just adding 8 or so capsules straight to the wort and giving it a little extra time with equivalent results. I haven't done this myself though.

I haven't had any contamination issues with the capsules - they appear to be pretty much pure lacto. Definitely haven't had any yeast contamination issues so far!

Agate said:

Swanson lacto-p

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never heard of this - is this what you are referencing?
http://www.swansonvitamins.com/swanson-probiotics-l-plantarum-inner-bowel-support-30-veg-drcaps

if so, how many do you use for 5 gals?

sweetcell said:

never heard of this - is this what you are referencing?
http://www.swansonvitamins.com/swanson-probiotics-l-plantarum-inner-bowel-support-30-veg-drcaps

if so, how many do you use for 5 gals?

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Yep, that would be them. I've had good luck with 3 capsules in a 1-liter 1.040 OG starter for a few days before pitching into a 5-gallon batch. And, they're shelf stable for several months!