Interesting observation of fermentation temperature

[JohnQ]

First batch in the brewhemoth.
We had the brewhemoths built with extra temp probe ports just above the top of the cone, I have one of my ETCs plugged in to it just to observe, as we haven't yet built temperature controllers.

The basement ambient temperature has been 60.5 F (15.8 C) plus or minus less than a half degree since the pitching of the yeast.

I chilled the wort to 63 F to pitch.

Since the fermentation began, the internal temp has steadily risen, and is now at 67 F, even though the ambient temp has remained constant.

With the ferment temp being 7 degrees above ambient, of course it makes me wonder what the ferment temp was when I consistently fermented at 70-72 ambient (with some success).

The ferment is vigorous right now, but is definitely slower than it was when I was doing the 70-72 ambient. It would have been done by now, and I've still got a couple of brix points to go, should be starting to increase the spund pressure this afternoon, and maybe be done by tomorrow morning.

JQ

[fakr]

that's interesting.  I found similar results with my first "liquid temp" experience.

I always set my fermentation air temp to 16C , and the stick on thermometer on the bucket always read 18-20.

Now that I'm maintaining a liquid temp of 16C, the air temp fluctuates between 10-12C.