Originally Posted by borealis
So does anyone else have this sort of temp swing? Is it possible that the thermostat is working correctly at a 3.5 degree differential and it stops the freezer from running at the right temp, but that the air temp continues to drop a little even after it stops running? It makes sense that just because the power is cut off, that the temp isn't going to instantly stay the same.
Sure its plausible....best thing to do is insulate the probe from temperature swings, which you will have if the probe is measuring the temp of the air and the door keeps opening/closing.
Another thing to check...you have have the thermostat on the freezer set to its coldest temp?
Another plus to strapping the probe to the side of your fermenter....you'll be monitoring/controlling the temp of the fermenter, not the temp inside your freezer...this way you don't have to compensate by dialing down the freezer temp a few degrees in order to get the proper temp of your fermenter.