This is a new one for me.
This particular style of beer (according the yeast package directions) requires a two stage fermentation. The first stage is at normal fermentation temperatures which, for me, are in the low 60°’s F. This will bring the beer down to a gravity reading of about 1.035. Not enough to finish for most styles and certainly not for this style which is supposed to be rather dry–in the single digits, as I like to say–around 1.006 or below.
The second stage requires that one bring the carboy or fermentation vessel up to a temperature of around 90°F. Well out of the range of my cellar temperature but possible nonetheless. I wrestled with several different methods for this and settled on the one pictured.
My first thought was the realization that the carboy would fit inside the large stock pot I sometimes use for brewing. With the temperature increase I was worried about increased fermentation-type activities which means the potential for kraüsen to re-develop and some possibility of overflow from the carboy. In order to minimize the mess I figured I would just put the entire carboy into the stock pot.
For insulation I used an old army parka that was in the basement. Seemed to be the perfect thing since it fit around the stock pot and was certainly insulated.
I then went through several iterations:
- heating pad under carboy in stock pot
- heating pad under stock pot, carboy inside pot
- heating pad on side of carboy between stock pot and carboy
- looked for a second heating pad (around here somewhere…) but couldn’t find it.
All the while the parka was wrapped around the outside of the stock pot but the temperature was not getting high enough. 😦
I finally went back to plan A (heating pad under carboy in stock pot) and wrapped the parka around the carboy itself between the carboy and the stock pot. Worked like a charm! Reached, and maintained, a temperature of 92°F.