I am building a starter off some dregs and was planning on cold crashing the starter and stepping it up next week, cold crashing again, decanting, and pitching. Its hf clara dregs that I am doing this with, and know there is sacc, brett, and lacto in the mix. My question is if I cold crash this starter, the brett and sacc will flocc out, but will the lacto come with? Or would there be enough in the slurry to sour my beer up regardless? Should I worry about the cell count? @OldSock , suggestions?
I have asked @jbakajust1 a similar question in the past, and his answer was that lacto flocculates (or at least drops to the bottom) if you cold-crash it. In fact, I've been led to believe that lacto reproduces faster than yeast, and if anything you might have a disproportionately high amount of lactobacillus when you pitch. But I wouldn't worry about that, it sounds delicious.
Ive grown lacto brevis up with a similar technique and it does drop out. It didn't seem to take longer (to drop) than Brett or sacch either.
Why cold crash? Why not just keep at stable temp (70 F) and step up by feeding it based on what you want to favor? Ie. Maltodextrin wort to favor lacto, higher IBU wort to inhibit lacto, etc... I don't get the point of cold crashing with such a quick turn around.
Hmmmm, this is a good question. I don't have it in front of me, but I seem to remember that in @OldSock's book he mentions that it's better not to cold-crash brett, but rather to let it settle out naturally over several days at room temperature. However, I could very easily be mis-remembering that part of the book.
Off memory, I believe Tonsmeire cited Yakobson's preference for holding Brett cultures at ferment temps. To me that makes more sense than crashing cultures, especially mixed cultures where different strains may be more/less flocculant than the others.
I mean, in fairness, if the culture is at all large, there is a lot of unwanted fluid there that I wouldn't want in my beer. So at the last stage, I would at least want to let the microbes settle and decant off as much liquid as possible.
I pitched dregs into a 1600 ml starter. I want to step it up another 1600ml and dont want to pitch 3200 ml of starter wort into my beer. Thats why cold crash.
The way I'm looking at this: You likely had your bottle chilled, poured off as much as you wanted while still keeping the yeast and bug within the bottle in order to make the dregs, so why worry about cold crashing the starter you've created? If anything, you've allowed all the good stuff to repopulate and you'll still have a good amount to pitch into your beer. I agree with SFACRKnight's post above mine, who wants to pour that much starter wort (now fermented malt water) into their beer? Not me. I've got a starter of dregs from Saison Bernice I'll be pitching into a saison within the next week and I've crashed and decanted it twice and all I see is progress in the population of the yeast and bugs. Cheers!
