During vigorous primary fermentation, the yeast produces a thick layer of foam called kräusen that can easily overflow a standard airlock. A blowoff setup routes this expanding material through a large-diameter hose into a separate bucket of sanitizer. This prevents pressure buildup that could rupture the fermenter or blow the lid off, while keeping environmental contaminants out of the tank.
Heard on the job
That hefeweizen yeast is so aggressive we need to rig a blowoff tube on tank three before it paints the ceiling.
Insider tip
Always ensure the end of the blowoff tube stays submerged in sanitizer, but be careful of temperature drops that can create a vacuum and suck the sanitizer back into the fermenter.
Also heard as
- blow-off tube