Low SG after lacto-fermentation - can I add more fermentables to up abv?

[EdiacaraBrewing]

I've seen a lot of threads that talk a little bit about this but still don't have a clear idea of what to do... basically- I am trying a berliner weisse, simple style as I read about in brewing classic styles, where you pitch lacto d w/ ale yeast after cooling the wort to 100 deg. after doing research here and at the lhbs, i decided to let the lacto do its thing first, and maybe let it go too long - pitched that tues nt, and didn't pitch the yeast (safale 05) until this morning. so about 62 hrs later. it was sitting next to a space heater that i bumped up to about 100 deg the whole time (but turned it off last night and let fermenter cool to 65 deg).

the OG was about 1.034, and the SG today was about 1.014. so i'm worried that the yeast i just pitched won't have anything to turn into booze. would it be crazy to boil up a pound of extract, maybe even hop it ever so slightly for some extra flavor, and add it to the mix? or add honey or sugar or anything? any thoughts would be super appreciated.

it's a 2.5 g batch so not the end of the world if it turns out nasty and non-alcoholic, but would be great to make something out of it if possible.

also i tasted the lacto fermented stuff last night and it just kinda had the banana hefe flavor, nothing too sour or tart unfortunately. recipe i did was approximation of the BCS one, 1# pilsen dme & 1# wheat dme.

thanks!

 

[porterpounder]

You could add any sugar source to bring up the gravity and allow the yeast to create some alcohol. You could also do a small separate higher gravity .5 g or 1 g batch with just the sacc, blend together and let it finish out together.

 

[EdiacaraBrewing]

ok cool, thank you! would you blend in the high grav mini batch after pitching or after primary fermentation? and are there any benefits of that over just adding the wort to the mess I've got going on?

another factor is that I'm going to be out of town until sunday so won't be able to do anything until Monday at the earliest.

 

[Calder]

Don't add any more sugar!

Sounds like you added the yeast too early. If you want a quick turn-around BW, do not add the yeast until it has soured to the extent you want it to be.

There are 2 basic types of lacto: Homofermentative and heterofermentative:

- Homofermentative produces only lactic acid, and doesn't change the gravity much since lactic acid is close to sugar in gravity.

- Heterofermentative produces both lactic acid, and ethanol, and lowers the gravity. You already have alcohol.

Just let it go and see what you get. A BW is a low alcohol refreshing drink, you really don't want to up the alcohol.

 

[EdiacaraBrewing]

Ok, but just read that lacto delbruecki, which is what I used, is homofermentative... So I'm still confused as to where all those sugars went / why the SG changed so much... Also why it smells/tastes so much like a hefe weiss...

I definitely hear you on the low ABV tip- not trying to make it super alcoholic, but just wanna make sure there's a lil sumpn sumpn in there.

 

[lshaner]

You had a "yeast infection." Even heterofermentative Lacto does not attenuate to that extent or that quickly. With so few remaining fermentables, you shouldn't expect it to get any more sour than it already is. If it were me, I would start over and use a different Lacto. The Lacto brevis offered by both WY and WL work well. Also the Lacto Blend from Omega Yeast Labs works at lower temperatures (70-95F) and sours really quickly (1-2 days). http://www.omegayeast.com/?portfolio=lactobacillus-blend

 

[EdiacaraBrewing]

Whoa, that is crazy. At least it tastes decent. And I guess that means it does have alcohol in it, so all is not lost. Will keep an eye out for that omega stuff, sounds excellent.

Fun experimental batch! Thinking I may dry hop or add fruit or something just for kicks.

 

[Calder]

You had a "yeast infection." Even heterofermentative Lacto does not attenuate to that extent or that quickly. With so few remaining fermentables, you shouldn't expect it to get any more sour than it already is.

Hetero lacto will bring it that far down. I've had it do it, and there was no-way I had a yeast infection. It almost didn't seem worth adding the yeast, but I did. ....... And if there are still sugars in there and the PH is not prohibitive, it can sour more.

For the OP: I'm not sure what to say about the low FG if the lacto was truly homofermentative. Whenever I have used homofermentative lacto, there has only been a small change in gravity