Blow-off room for lager

Seems like a few lager posts recently, so I’ll keep it going…

Gonna brew a helles in a couple weeks, and I need to make sure I have my process set up right. I decided to bust out my old lagerator (aka old college dorm fridge that I janked up and never used) and give it a whirl. My main problem is that due to the step in the fridge where the compressor is, I have a limited height at which to stick a 6G carboy. The carboy is a bit too tall sitting on the step with an airlock, however I found that a blowoff tube could be inserted and bent over to allow the carboy to fit in the fridge. When the blowoff tube is bent over, there is an obvious crimp in the tube and the space for C02 to escape is very tight. The tube is large enough to plug the carboy neck on its own.

Not having much experience with lagers and blow off tubes, I’m not sure if having such a small amount of space presents any problems. I’m pretty sure there is at least SOME room for CO2 to escape, but certainly not enough space if there is an active fermentation and yeasties clog it up. Are lager ferments fairly calm given the low temp? Anything I need to worry about?

Also open to other suggestions for a short airlock, but this seems to be the best idea I could come up with.


lagers are so slow i don’t even use an airlock, just tinfoil.

Well that would make this a billion times easier, thanks!

No risk of oxidation or anything like that? Would there be enough CO2 present during the long term storage to keep the brew covered from O2?

I still use an airlock, but yeah, I’ve never had anything even close to a blow off with a lager. If you keep it at the correct temp you should be fine without one.