I tried to find something about this topic; no luck. So here's my question.

Beside the fact that my beer went crasy and took control of my airlock liquid ahah, could you tell me what is that white sediment on the bottom? Is it yeast or sugar, or something else? Is it normal? I'm not actually worried about the beer itself, but I just want to know.

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Thank you


  • 1
    Looks like yeast to me. Not enough head space?
    – Mołot
    Commented Dec 12, 2016 at 8:43

3 Answers 3


Looks just like yeast to me. If foam rushed into your airlock, this is really probable. Sugars are dissolved and you won't see them as a layer.

I would replace the airlock with clean one - that way, you wouldn't have to worry what it actually is.

  • 3
    Second that. It's yeast from lack of head space in the carboy. Change it out. Commented Dec 12, 2016 at 14:02
  • 1
    Exactly, the airlock is full of beer anyways, it has to be changed and cleaned...
    – Philippe
    Commented Dec 14, 2016 at 15:08

Ditto, most likely yeast. Try and use a "blow off tube" next time as the krausen is forming, usually during the first few days after the start of fermentation.... depending on fermentation temp, type of yeast, etc. When krausen falls or as it is falling replace blow off tube with a sanitized airlock. This link has some images of blow off tubes. Brewing blow off tube images!


Absolutely it is just yeast. I also use a blow off tube for primary fermentation. There are two main benefits. First, it allows all the pressure to escape as fast as it can be generated without mucking up your airlocks. Secondly, it allows some of the krausen to be removed without risking contamination. Charlie Papazian's book, "The Joy of Home Brewing" shows you how to use a blow off tube.

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