Me and my friend made a hefeweizen a time ago and this beer had a strange behaviour, when we open the bottles the foam grows up fast until get out of the bottle.

The beer is ok, in fact it tastes great, but we don't know what we could made to this strange foam behaviour happens.

We have never experienced this on our batches, only on this hefeweizen.

Someone have an idea what causes big foams growing up after open the bottle?

2 Answers 2


Its one of the following:

  1. Incomplete fermentation leaving residual sugar in the bottle.
  2. Too much priming sugar. Which would also be amplified as a problem if #1 is the case.
  3. You inadvertently picked up an infection and the non-fermentables along with the priming sugar has led to over carbing.
  4. Your opening the bottles warm and the CO2 is no longer dissolved in the beer.

Wheat beers tend to have extra protein and hence foam stabilizing properties. But the foam shouldn't climb out of the bottle when opened normally. Only you can decide which of the three possibilities it is.

  • Well, I think it was the first option, incomplete fermentation, because we don't use too much sugar in primming, we take care of sanitization in all equipments, and we always drink this beer when it's cold. Thanks for this clarifying answers!
    – loop0
    May 12, 2010 at 14:22
  • I agree with brewchez. I suggest you just leave them in the bottles for a week or two and then try again. May 13, 2010 at 17:54

What was the final gravity? How long did you ferment before bottling?

I'm guessing that there were residual fermentable sugars (i.e. fermentation wasn't complete) or you used too much priming sugar when bottling. Either way, the yeast had too much sugar left to consume inside the bottle and produced too much carbonation.

If you hit your final target gravity, and checked it a couple times (with a couple days in between) without the gravity dropping any further before bottling, then fermentation was likely complete and it was simply a case of too much priming sugar.

If you didn't check to make sure that fermentation was 100% complete, it could be one or the other, or a combination of both.

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