A chest freezer is a pretty tightly sealed environment. Is it necessary to vent the freezer while fermenting a lager? There is a defrosting drain plug at the bottom that I can remove and possibly replace with a foam plug…
I don’t have my freezer vented, and almost gagged opening it up once during a vigorous ale fermentation w/blowoff. I’m interested in the available approaches.
I don’t know about the drain plug option…
putting a hole in a freezer would kill the electric bill. If you want to vent just open the door once a day.
Yeah. You could cut a hole in the top and stuff a snorkel in there 
I have a small chest freezer that holds one carboy or cornie keg. I don’t vent it. I do open the top about every day though, not to vent, but to move the temperature probe wire so it does not leave a permanent dent in the seal.
Here’s a little warning. I had a carboy spew out its krausen and it coated the sides of the carboy and the bottom of the freezer real nice. While leaning down into the freezer to clean it, I noticed something. The oxygen was displaced by the Co2. It didn’t take long to figure out it was hard to breathe. So be careful if this happens to you sometime. Leave the lid open for a while before sticking you head in to clean the bottom.
If you’re really concerned about venting the chest freezer, you could just prop the lid open a crack. Cold air stays lower so it shouldn’t hurt too much. I personally would just open once or twice a day and I usually do out of curiosity.
