I just started my first batch of homebrew using a kit from Brooklyn Brew Shop, and 15 hours in, I seem to have a problem: The fermentation seems to be very vigorous and I have this foam/gunk/residue that has made its way into my blowoff tube (pictures attached). As of this writing, it looks like some wort has also gotten into my jar of sanitizer as well.

Should I be concerned about this? Is this a contamination risk? At this point would it be better to clean out the blowoff tube, or would I be better off waiting for the fermentation to subside and to replace the blowoff tube with the airlock a couple of days later as recommended in the instructions?



1 Answer 1


No worries. This is exactly the point of a blow-off tube: to blow-off excess fermentation products (krausen and wort trapped in the bubbles) in a controlled, "sanitary" way. There's basically no contamination risk. Swap out the contents of the blowoff container if it gets too nasty, starts attracting fruit flies, &c. But leave the blow-off tube in place until fermentation subsides. At that point, as you say, probably best to replace it with an airlock, or just cover with tin foil or whatever.

  • Ah, i suspected as much but couldn't find a clear cut answer. Thanks! Nov 15, 2014 at 22:48
  • 1
    +1 for swap the content of the blowoff container. It no hurts at all, is easy to do, and is better than let the thing full of krausen thing, wort, yeast, etc. If you will stay with the blowoff, just clean the thing and put it again with new sanitizer.
    – jards
    Nov 15, 2014 at 23:07

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.