Heating a Temp Controlled Fermentation Chest

[DsmBrood]

I have a 21cf freezer chest that I use as a fermentation chest in the summer. It sits in a non HVAC controlled, but insulated work shop. Today I brewed a Belgian Spiced Strong Ale, and pitched it with Wyeast 1388 and have it in the freezer chest. Now the high temperature today was 30 degrees, so clearly I’m going to need to heat the freezer to keep fermentation temps in range. So I drop a small space heater in there, hook it up to my temp controller, set it to heat mode and dial up 65 degrees. I chilled my wort down to 55 for pitch, that means I need to get my wort to climb 10 degrees to be within fermentation range. My temperature probe is in a termo-well inside my wort. With my temp controller set to 65 the ambient air temperature inside the freezer is up to 90+ degrees before my wort temp has started to drop.
Question for the group is: what experience have you had with this situation and how have you managed it? I don’t want to just let the heater run until internal temp hits target, because by then my ambient temp and exterior will be hot enough to kill the yeast.

 

[hillhousesawdustco]

You could tape the probe to the outside of your fermenter to measure the borderline of ambiant/wort temp and then put it back in the thermowell when you are ready to control just wort temperature.