I use 1 litre swing-top bottles to make kombucha. Yes, I know it's not really homebrew in some people's eyes, but I figured someone here could help.

Depending on what ingredients I use, sometimes I have a bottle with a lot more than the usual amount of pressure. (Usually, I can just pop it right open.) With these higher-pressure ones, I have to manually hold the top open ever so slightly to bleed off the pressure, or open it suddenly and loose about 30% of the tasty beverage.

Is there any way to prevent this, and bleed off the pressure without me having to hold the bottle for 10 minutes?

Edit: I should have elaborated further. The times when there's way too much pressure is when I bottle it with a fruit additive, so there's lots more sugar in the bottled product than a normal one, sans fruit.

  • when you make the Kombucha, is it very well mixed before you bottle it? are your bottles sanitized and how? are you opening some that you have not chilled all the way for at least 24 hours? infection, variance in how well the liquid is mixed before bottling, and temperature (it takes time and cold temperature for all the Co2 to dissolve into the kombucha) can all cause what you describe.
    – DaFi4
    Jul 26, 2016 at 8:16
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    I had overcarbonated swingtop bottles once and could just open and immediately close them again. Had to do that a for a few days in a row (once per day), but it eventually worked.
    – Robert
    Jul 27, 2016 at 15:02
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    @montewhizdoh I should have mentioned that the difference in the overcarbonated ones is that they are bottled with fruit, so there's way more sugar than usual Jul 27, 2016 at 15:38
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    @LeviBreederland I do not think you are experiencing a gusher infection, you just have too much sugar left in the bottle. You need to come up with a way to make the amount of sugar predictable that works for you. In beer brewing we normally let the fermentation complete before bottling (including all fruit, etc). We add a last dose of priming sugar at this point before bottling. Mix it well, if you decide to go this way. Yes, There are other ways such as counter pressure fillers, etc.
    – DaFi4
    Jul 27, 2016 at 16:01
  • You are playing a dangerous game there, the over carbonated bottles could just as well just explode like a grenade due to the excessive pressure. Can't you wait for the fruit fermentation to finish before bottling? Aug 13, 2016 at 15:00

2 Answers 2


What you're describing is a "gusher infection", wild yeast that can consume normally unfermentable sugars like dextrins. Usually leaves a beverage with little body and other issues.

In beer after the cap pops a gusher will just usually slowly volcano, taking most the beer with it as foam. Some can over carb so much to vacate the bottle almost instantly.

As far as your kambucha getting it very cold 33°F and slowly releasing the CO2 is the only solution. Unless you have access to hyperbaric chamber. :-)

Better sanitation and a fresh scoby should rid you of the wild yeast in future batches.

  • In my original post, I forgot to say that the times that it's overcarbonating are times that it's bottled with more sugar content, because of adding fruit. Jul 27, 2016 at 15:37
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    @LeviBreederland if the fruit isn't pasteurized it will very likely have wild yeast Jul 28, 2016 at 3:39

During secondary fermentation (bottling stage, aka 2F) of kombucha brewing, there is a correlation between sugar as an input and carbonation as an output. If you increase the sugar in the 2F ingredients, carbonation will increase. If you're getting too much carbonation during 2F, you can do one or both of the following.

Burp the bottles throughout the 2F process. If you suspect there's a lot of carbonation building up (because you've added fruit, or you have a test bottle set up to monitor carbonation levels) simply pick an interval (daily, etc) and open the bottle. Doing this will prevent over-carbonation.

And/or, vary the amount of sugar being added as an ingredient to 2F when bottling. Add less fruit. Or, if you like the amount of fruit your adding, then you need to decrease the amount of sugar in the kombucha fluid you're bottling. To get a less sugary kombucha fluid, allow your primary fermentation (1F) cycle to run longer. For example, if you bottle after day 7 in 1F, wait for day 8, 9, 10, etc to bottle.

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