I have a batch of beer, fermented and then bottled. When I open the bottle, there is a lot of foam and it flows out of the bottle for a while.

What could cause this? I assume it's too much CO2 and thus too much priming sugar? (This is a 5 Gallon Batch, mixed with Water/Sugar in a bottling bucket, so no Fizz Drops)

Should I leave the bottles alone for another week or two? Could temperature cause it? (Temperatature varied between 68 and 76 degrees F during the entire process)

Some more information:

  1. I used the White House Honey Ale Kit and brewed on 1/24/2013
  2. Cooled the Wort in a Water Bath. I didn't have a Wort Chiller at the time and it was hard to get the Water cold enough, so that process easily took 45 minutes. Original Gravity was lower than expected (I think 1047 instead of 1062), Final Gravity was 1011.
  3. Put it in a 5 Gallon Fermenting Bucket and let it sit there (I don't have a secondary fermentor, although I'm about to order one)
  4. Let it sit in my closet, temperatures between low 60's and mid-70's (my AC can only set to either heat or cool, so controlling the temperature is an issue)
  5. Bottled on 2/21 with the provided 5oz of priming sugar
  6. Opened a bottle on 2/27 => Beer was foamy, a little foam rose and escaped, beer tastes a bit flat

Possible issues I see:

  1. Took too long to chill
  2. Only one fermentor
  3. Lack of good temperature control
  4. Opened too early after bottling

Since I do not exactly know how each of these factors change the taste, I'm not sure what's really causing it. I bought a Wort Chiller and I'm about to buy a secondary fermentor, but I can't do much about the temperature unless someone has an idea.

  • Did you use a hydrometer? Readings from that would be useful. You waited a month though so it is unlikely it didn't finish. Feb 28, 2013 at 5:16
  • @ChrisPlaisier Original Gravity was lower than expected (I think 1047 instead of 1062), Final Gravity was 1011. Feb 28, 2013 at 5:25
  • 1
    You can slow swings in temperature by putting your fermentor in a larger container filled with water. This increases the "thermal mass" of the system which slows the temp change in the fermenting vessel despite swings in ambient temps.
    – brewchez
    Mar 1, 2013 at 0:31

5 Answers 5


One of three things:

  1. Incomplete fermentation prior to bottling... If the beer wasn't completely done before bottling residual sugar (plus priming sugar) is over carbonating the beer.

  2. Too much priming sugar. Re-examine how much you used. Consider that if the beer was significantly cool prior to bottling that a fair amount of CO2 would have been already in the beer post fermentation. Hence the priming sugar needed to be adjusted. This shouldn't really be a problem if you were fermenting it as an ale as you indicate.

  3. A contaminating microbe got into your beer and that microbe is fermenting away on the non-fermentables left by the brewers yeast. It is possible to have a contamination that creates gushers prior to really tasting any off flavors as well.

You might be able to rescue the brew by venting caps by lifting them partly and then re-capping to off gas some of the CO2. If you can chill the entire batch of bottles down to fridge temp, you might prevent more CO2 from developing. Also storing them super cold prior to opening might help keep some of the CO2 in solution. In reality, if you have gushers, there isn't alot you can do to remedy it now. Sorry.

  • +1 for a thorough answer! What would be helpful is link or some text describing how to recognize a gusher, other than by the amount of co2/foam produced.
    – mdma
    Feb 28, 2013 at 2:53
  • Thanks! Would #3 also cause a flat taste? I'm updating my question with a bit more information. Feb 28, 2013 at 4:27
  • You need a link to know that when a bottle foams over its a gusher? I don't understand what you would have been looking for.
    – brewchez
    Mar 1, 2013 at 0:26
  • 1
    It is possible if the unfermentables being consumed in #3 are chewing up some nonfermentable sugar like compounds meant to give the recipe taste. But its also possible that the unfermentables being consumed are more of the body forming compound. Which would make the beer seem thin.
    – brewchez
    Mar 1, 2013 at 0:29
  • Chilling down made a good difference for this batch. For the next batch I'll keep a closer eye on 1 and 2. Mar 4, 2013 at 9:47

One possibility is uneven blending of the beer and priming sugar solution. Did you mix the sugar/water solution yourself, or just let it mix naturally from the beer being racked on top? Depending upon how viscous it is, it can sit at the bottom of the fermenting bucket even though the beer is swirling. This means you end up with some bottles undercarbonated, while others are overcarbonated.

Some people try to use as little water as possible in the priming sugar solution, so not to dilute the beer too much, but this can backfire! Best to use a little more water to be sure it's uniformly mixed with the beer.

  • I put 16 oz Water/5oz sugar to a boil, put it at the bottom of the 5 gallon bottling bucket, added the beer from the fermentor, then gently stirred with the siphon. I'm afraid to stir too much because of Oxygen getting into it, but truth be told, I don't know if Oxygen during stirring is even a problem. Feb 28, 2013 at 4:36
  • 1
    I forgot about this option, and its a good one. The OP should take a bottle from a different part of the case, and see if its a gusher too.
    – brewchez
    Mar 2, 2013 at 14:09
  • Gently stirring won't cause oxidization - it's splashing that's the main issue. 5 os sugar in 16 oz water is 31.2% brix, or about 1.120 SG. That's going to be fairly viscous. but not uncommon for priming solution. When I bottle prime, I tend to pour in the sugar solution after a few quarts of beer are in the bucket to help dilute it without it sticking to the bottom.
    – mdma
    Mar 2, 2013 at 14:15

Sometimes when opening a beer to early after bottling, it will foam, and taste flat. Especially when you have high carbonation. 5 oz in 5 gallons equals a co2 volume of 2.9 which is quite high for an american ale. When I bottle my belgian ales I usually have a carbonation around 3. These will foam if opened too early but after a few weeks they will have a nice carbonation and wont foam at all when opened.

I would wait a few weeks and keep them in a safe container before jumping to any conclusions. After two weeks put one in the refrigirator and leave it there for a day before opening. if it still foams then you have bigger problems.

If you see something that looks like a white ring of sediment in the bottle around the neck, then you probably have an infection.

  • 2
    Keeping the beer cold for a few days before opening will help, as colder temperatures allow the CO2 in the headspace to be absorbed into the beer. Feb 28, 2013 at 17:42

FWIW ... I used to make root beer from scratch, using either champagne or ale yeast for carbonation. SWMBO used to open the bale-top bottles with a bit too much of a flourish, and they would gush every time. I would open them very gently, very slowly, with no problem. So I had to train her to take it easy, because it seemed obvious to me that popping the bottle very suddenly would lead to a violent gushing reaction. Not sure if this is a factor with your gushers, but perhaps it's worth considering.

By the way, absolutely no innuendo is intended by this post. ;)



This is called gushing, and you usually get it with a combination of two factors:

  1. A lot of CO2
  2. A lot of "crystallization nuclei" for the CO2 to build bubbles and gas out

I currently have such a beer - I added more sugar in order to get more than usual CO2 and something went wrong during the brew and the beer got very cloudy. Every bottle I open gushes almost immediately.

Once you have that, there's not much you can do. Cooling the beer down to almost freezing temperature and then pouring it out immediately after opening the cap.

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.