I just pitched my first batch 36 hours ago, and I think I might be having some problems with temperature regulation already. I used the ‘Caribou Slobber’ kit from this website, and everything on brewday seemed to go well. The only issue was that there was just over an hour between taking the wort off the boil and pitching the yeast. However, the beer was 68 degrees F when I pitched the yeast (Danstar Windsor Ale Dry Yeast), which I thought was pretty good. The kit instructions say the optimum temp for that yeast is 64-70 degrees F.
I kept the glass carboy in closet with 68 degree air temperature, with the cardboard cover over the carboy. The next morning, it had already started fermenting and seemed very active already, with the temperature risen to 71. In the evening (about 18 hours after pitching), the temperature had risen to 72, and there was a LOT of movement and activity in the carboy, with about 3 inches of foam on top. I decided to remove the cardboard cover and hope the 68 degree ambient air would cool it back down to 70 or so.
Then, we left to go drink some beers at a friend’s house. When we returned (27 hours into fermentation at this point), the temperature had risen to 76. Sludge on the glass indicated that the foam cap had come very close to a blowoff while we were gone, but then receded back down to a 5 or 6 inch cap of foam. The beer was swirling around like crazy, and bubbles were coming through the lock almost constantly. I was pretty worried that the yeast was going to burn out all of the sugars too quickly and make an off-taste. So, I put the glass carboy in a bathtub filled with 65 degree water before bed, hoping it would cool the beer down to about 66 or 67.
This morning (now 36 hours after pitching), I found the beer cooled down to 66 as I had expected. However, the fermentation has slowed almost to a standstill now. The difference has been (figuratively and literally) night and day overnight. Small bubbles now only come through the airlock once every 6 seconds or so, and the foam cap has died down to just a very thin (1/8 inch) layer. The beer doesn’t seem to have much movement or activity at all inside.
First of all, is this a big problem, and should I be worried that this will be a bad batch? Second of all, what did I do wrong? Is there anything else I should do to try and make the best of the situation? I put the fermenter back in the 68 degree closet, with the cardboard over it again.
As a side question, is it ok that when moving the carboy, the beer was sloshed around quite a bit inside, and the foam cap was disturbed?
Thank you for reading this excessively long post. I appreciate any help I can get!