I ferment my beer in a fridge that has a unit that keeps the fridge within 1 degree of 60F. I've scrubbed this fridge with soap, and even bleach and believe it to be relatively clean. I know I'm going to get quoted on this and made fun of, so let me explain. What I mean by clean is it's in new condition, it's not a fridge that sat in some guys basement and should have nuclear waste stickers on it. It was my kitchen fridge and never had problems before. There's not 30 years of crud built up or anything. But I keep getting black mold on the door now. My guess is because of the extra moisture in the fridge from the blowoff tanks and the higher temperature. I scrubbed it with bleach and it came back, scrubbed it with bleach a second time and it seems to be gone finally. I want to make sure I don't have this problem again. I'm sure some of you have run into this. How do I keep the mold from coming back?