Well, I did get around to putting a collar on my mini-fridge to serve as a fermenting chamber in which I can also cold crash... And it worked like a charm! Holds temperature exceptionally well, even down to 2-degrees Celsius. The composition is 5/8" dimensional spruce, a 1/2" layer of purple hard insulation (do not recall the R-value), and 1/4" puckboard with caulked seamlines to clean it up and look proper. I mounted a ceramic heating bulb in the back upper left, and a PC fan mounted to the collar using L-brackets sandwiched between the wood and insulation. The only thing I am missing is the ability to force-carbonate, as the front-to-back space won't allow my carb stone to fit. But I built a platform in my keezer to perform that task. Here are a couple WIP photos as well as the final look inside holding my Spike Flex+, which is currently fermenting out a citra-IPA.