Fermentation temperature

This is a very basic question. The Wyeast 1272 American Ale II comes with a temperature range of 60-72 deg. Does this range refer to the ambient temperature, or the temperature indicated on the Fermometer? The reason that I ask is that I read somewhere that the fermentation is an exothermic reaction, and therefore the temp inside the fermenter could be as much as 10 degrees warmer than ambient. So, I have my fermenter in my frig with a temperature controller. Should I control the temp in the frig so that the frig “ambient” temp is 60-72, or so that the temp shown on the Fermometer that is attached to the side of the Fermenter is 60-72

It always refers to the beer temp, not ambient. My experience is that my beer turns out much better by staying at the low end of the range.

that range is the beer temperature, not ambient. what you’ve heard about yeast being exothermic is true, although i’d estimate closer to 5 degrees warmer than ambient.

I would set your fridge to the lower end of the range 60-63 and keep an eye on the fermometer.

edit: woops, denny beat me too it :cheers:

I take a wash cloth folded twice and wrap it to the fermenter with an ace bandage. Then slide the sensor underneath, and set the controller to the temp I want the fermenting beer to stay at. Bump up the temp on the third or fourth day so your fridge doesn’t cool down while the yeast is cleaning up fermentation by-products ( this is really only a concern when using more flocculant yeasts).