After hearing good things on this forum about combining Windsor and Notty for bitters, I did so, and the fermentation is doing fine on day 4–and the aroma is great.
But I noticed something curious earlier today–after the airlock activity had fallen to about 5 bubbles per minute yesterday, today it shot up to 13 this afternoon, even though the krausen had started to drop and the beer was clearing in places. But tonight, it was back down again–to 2, and so I’m just wondering what might have happened/ I’m not alarmed at all, just curious.
Could it be that one yeast operates at a different schedule? I’ve had experience with Burton yeast rising, dying, and rising again, so maybe this was a minor version of this phenomenon.
Windsor works EXTREMELY fast – it’s pretty much the fastest yeast on the planet. It will settle out and refuse to ferment at all anymore about 36 hours after pitching. After that the Notty no doubt took over the rest of the way. That makes perfect sense to me.
Funny you should ask about the temperature, Jim. I didn’t change the temperature setting for the heating wrap that I use, but just tonight I went to check on it and the wrap turned on when the temperature hit the low setting (66), and, voila, the airlock started gurgling again. So this makes me think there wasn’t any revival in the fermentation necessarily–just that the trapped gas expanded a bit with the heat–because the beer temperature itself didn’t change that quickly. I’ve never seen this before, either, but that’s probably because I just haven’t watched long enough.
Thanks, DMTaylor, for the insight about Windsor–I’m sure that explains the quick start I also experienced.
Anyway, I can’t wait to taste the finished product because the aroma from the airlock is great.