Brew temp question?

What is the difference between the inside and outside temperatures of you abode? It depends on the activity of your furnace, wood stove, etc. and upon the quality of your insulation.

In the case of fermenting wort, the conversion of sugar into alcohol generates internal heat to the wort.

Anywhere from a couple degrees up to around 10 degrees (F), depending on how vigorous the fermentation is. The reason for the difference is that fermentation creates heat.

John.

Onli in the cell multiplication phase ,(right after pitch ) during the lag period will you see a major heat production because the yeast is aerobically respiring, producing far more heat than when the low energy fermentation (anaerobic) process occurs after lag time is ended. 5 degrees textbook.

The only time to worry about it is if your room temps are approaching the upper temperature definitions of the yeast you are using, then you risk esters or "funny tatses"

I chill my carboys to 67 dF and dont worry about it and have a home brew

yodar

Note that yeast in wort don't actually have seperate reproduction and fermentation phases. They do both at the same time. The only reason this matters is that fermentation is beginning to occur during the lag phase, so if your temps get too high it can lead to by products.

John.