Ok, I searched on this, but I couldn't find anything. Here are the details.
I have a 7ish cubic foot freezer with a Johnson temp controller set at 40. The probe is mounted on the wood that is a part of the collar. The collar is not insulated other than the wood itself. This summer when it was 90 my thermo I have in the freezer read like 38 and I had some frozen beer. The thermo and the probe for the controller where high in the freezer so I figured hot air rises and maybe it is cold at the bottom and not so much at the top. So I installed a fan to circulate the air and it seemed to get better. Well now it is 35 or so at night and mid 60's during the day. Now my thermostat in the fridge is showing 48 and the beer tastes hotter. I also took the probe off its mount and left it in the middle of the freezer and still 48. The only other thing I can think of is that the majority of the probes wire it outside the freezer. If you know the Johnson controller it is this weird stiff copper wire. The next step is to get that in the freezer, but that is a wild guess. Sorry this is so long. Any ideas.