Is there a reference material that any one can point to relative to yeast tolerances to pH? I pitched a lacto tri-blend from Omega that overnight went 4.3 pH to 2.9! (Image and used a lacto starter). I have thirteen gallons going into a boil and expect to have 11.5 or so gallons of Berliner weisse wort to pitch a one gallon starter of 1056 into and I am wondering if it can tolerate the low pH? Worst case, I will pitch a Brett Vrai later, if it doesn’t ferment out with the saccharomyces.
I will be scouring American Sour Beer and Yeast, but I thought I’d ask hear.
S. cerevisiae can handle a pH of 2.9. However, fermentation can be sluggish at that pH level, and one runs the risk of the fermentation stalling. You may find that you need to buffer the pH back up to over 3.0 using carbonate or bicarbonate. I had a batch of mead stall on me when the pH dropped below 3.0. I buffered the mead back up to over 3.0 using K2CO3 (potassium carbonate), and fermentation resumed.
I’ve had similar results with the Omega blend. I use 1007 and have had no problems with fermentation, other than being a lot slower than usual. I think Martin recently mentioned having success using your strain in a BW at a pretty low pH.
Thanks for the input - so add carbonate (I have calcium carbonate) at the end of the boil so it doesn’t precipitate out? Any idea of how much to start with the addition (I don’t want to overshoot and lose acidity above 3.5).
I have something that says 5/8 teaspoon per gallon lowers acidity .15%, but that may not be a reliable reference (it’s just printed on the packet from the LHBS)…Glad that some guys are checking the forum on a holiday!
I skipped the CaCO3 and the large starter got it going, though, as mentioned, it was sluggish. It is well on its way at this point (day 4), so I will draw a sample for measurement and taste this weekend, most likely…expecting sour to the point of blending required. I have a blonde that is finishing and it will be the blending batch.