Today I hooked up the raspberry pi to the fridge and added some code to control turning the fridge on and off. If the temperature is 2 degrees below the set point then the fridge turns off, if the temperature is above the set point and it's been atleast 10 minutes since the last on-time then the fridge turns on. That extra time delay is intended to minimize the number of times I turn the fridge on/off. I expect to be updating this logic as I brew a few more beers and get a feel for it. I've got 2 beers in the fridge right now which have been in there for about 2 weeks - a Gumball Head by 3Floyds clone and a Hazy IPA.

The output below shows timestamp, temperature, relay status. Here you can see the fridge shutting off once it cools down to 68F. Commit: 6236f98