It’s pretty much unavoidable. Most kombucha brewers
are familiar with their bottles of kombucha being a little
over-active sometimes and fizzying over or making a mess.
Even if you have your process down to a T, it can still be
hard to predict. This is a living thing, after all, and lots of
changes in your brew’s environment can affect how it
A note about burping...
I know a lot of homebrewers will say that you should burp
your bottles to prevent over-carbonation. And while I agree
that this is definitely an effective way to prevent fizzy messes,
I actually believe that you do not need to burp your bottles. I
think it’s counter-productive to creating good bubbles. It’s a really effective way to release too much carbonation from your bottles. And besides, it is possible to prevent over-carbonation without relying on burping. You can read more about why I’m anti-burping here.
But in any case, here are tips to help minimize messes and prevent over-carbonation.
Chill your kombucha before opening. The cold helps to distribute the carbon dioxide into the liquid and “calms it down.” Cold temperatures also slow down yeast production. So the yeasts don’t continue to ferment at a rapid pace and produce as much carbon dioxide as they would if the kombucha was room temp. I usually don’t let my second fermenting bottles sit at room temp for longer than 3 days before moving to the fridge and testing them.
Open it slowly, over the sink. And when I say slowly, I really mean slowly. Usually, you’ll be able to see the carbonation build up as you open it. This is another good reason to use clear bottles! If it looks really aggressive, don’t open it all the way, and release the pressure slowly. Have a cup/bowl handy to catch any spill-over so you don’t waste kombucha.
Don’t shake or agitate your kombucha. I know that can be hard sometimes if you’re grabbing one out of the fridge on the way to work. I just do my best to remember to open it over the sink before I leave. Then I re-seal it and head out the door.
Use the plastic bag trick. Place the bottle in a large bowl, then take a sandwich bag and place it over the opening to protect yourself and your walls from the spill. Open the bottle through the plastic (with your hands outside of the bag). Any spillage will basically “fountain” up into the bag, then back down into the bowl. Then you can pour it back into a glass and drink it. If that explanation was confusing, watch the video for a demo!
That last tip is a great option if you know you have a really aggressively bubbly bottle. Sometimes you can tell it’s too fizzy as you’re opening it. Or sometimes you just know it’s over-carbonated — maybe you bottled with a fruit flavoring that turned out to be really fizzy when you opened a bottle from the same batch, and you want to avoid having the same mess happen again. Maybe you left it fermenting in the bottle at room temp for way too long or forgot about it in a hot car. Hey, it happens, we’re human!
And a mess here and there is normal. But I honestly haven’t had a mess since I first started brewing about a year ago, so even though I never burp, I know that my process and methods have definitely helped me keep kombucha off my ceilings.
Don’t forget: Yeasts can re-awaken and keep carbonating at room temp
If you leave your kombucha bottle sealed at room temp even for a few hours, the yeasts will reactivate and start eating the sugars again to produce more carbon dioxide. So even if you’ve already finished your second fermentation and put your bottle in the fridge, as soon as you take it back out to room temperature, the yeasts can wake back up. And it can start carbonating again if you seal the cap.
So if you’ve left a half-finished bottle of sealed kombucha in your hot car and think that you can open it without making a mess, that might not always be the case, depending on how active the yeasts are and what you flavored with.
So just be mindful about sealed kombucha bottles that have been sitting at room temp for a while.
Note: This primarily only applies to home-brewed, raw kombucha. This doesn’t necessarily apply to store-bought kombucha because who knows what yeast inhibitors or practices they use to halt their fermentation processes in the bottle. (They say they’re raw products, but the FDA doesn’t really regulate labels that say “raw” for accuracy.)