Has anyone compared internal fermentation temperature with the temperature of the blow off jar? My guess is they would be pretty close since they are in the same ambient temperature and the blow off gas is the same temperature as the fermentation temperature or very close to it. Right now, my blow off jar is 1.4F hotter than ambient. I suppose I could crack the lid and measure the temp, but it would get messy. Hence, the question.
You probably lose a few degrees from the tubing and the greater surface area to volume ratio in the jar. I'd guess it's at least two degrees warmer in the fermenter.
yep, actually measured it once and found a 1 degree F difference with the fermenter being the warmer of the 2 vessels. my blow off is a small plastic pail, about 1.75 gallons, and the old celler is coolish.
