Why Isn’t My Kombucha Fizzy? 10 Ways to Fix Flat Kombucha!

Is your kombucha not as fizzy as you would like? We’re walking through all the reasons your kombucha isn’t carbonated (and how to fix it)!

kombucha not fizzy

There’s nothing quite like the proud feeling of achievement when you crack open a bottle of fizzy homemade kombucha, all carbonated and bubbly and delicious. The flip side, of course, is when your kombucha isn’t fizzy and you start to wonder where you went wrong (in kombucha? in life?).

So for all the folks with a sad bottle of flat kombucha on your hands (we’ve all been there), this is your troubleshooting guide to help you achieve carbonated kombucha success!

fizzy kombucha bottle

What is carbonation?

Carbonation, put simply, is carbon dioxide (CO2) dissolved in a liquid. In kombucha, the yeasts in your brew eat the sugar and use it to produce alcohol and CO2.

In the first fermentation, the kombucha is covered only with a cloth, meaning the CO2 can escape and doesn’t stay in the liquid. That’s why we do a second fermentation, sealing the kombucha in airtight bottles and trapping the CO2 in the kombucha.

This method of carbonation is called natural carbonation. Another method is called forced carbonation, and this is when machines are used to artificially add carbonation to a drink. Drinks with forced carbonation include carbonated water, soda, and even most store bought kombucha.

While natural carbonation produces a soft feeling, with smaller bubbles and less tingle, forced carbonation is just the opposite. Forced carbonated drinks are usually sharp feeling, with large, uniform bubbles. This is an important distinction, in that you should not expect your home brewed kombucha to have the carbonated feeling of a soft drink.

With that said, you can make some seriously carbonated and fizzy kombucha. Here’s how!

pouring juice into kombucha bottles

How to carbonate kombucha

To carbonate kombucha, you’ll essentially just transfer your uncarbonated kombucha into airtight bottles, add something sweet as “food”, seal shut, then wait for the bacteria and yeasts to work their magic!

While some carbonation does occur in the first fermentation (the SCOBY can create a light seal, trapping a little fizz in the brew), most of it occurs in the second fermentation Read more about how to brew kombucha here.

kombucha in bottles with a mango

So why isn’t my kombucha fizzy?

This brings us to our question of the hour – why isn’t your kombucha fizzy? This is one of the most common questions we get in our kombucha Facebook group. There are numerous reasons why your kombucha might not have carbonation:

1. You’re not using the right bottles.
You need to use fermentation grade bottles to brew kombucha, as these are specifically designed to not only trap air in, but withstand the pressure build up without exploding or leaking. These flip top bottles and these Grolsch beer style bottles are both great. For the best buch, avoid decorative bottles and mason jars.

2. You need to adjust your first fermentation time.
Your first fermentation needs to run long enough that there are plenty of bacteria and yeasts built up in the kombucha – these power the carbonation reaction. On the other hand, you should ensure your first fermentation isn’t going so long that your kombucha tastes sour/vinegary – there needs to be some sugar left for the yeast to feed on to help power the carbonation.

3. You’re not letting the second fermentation go long enough.
This one is simple; you may just need to let it (second) ferment longer! A typical second fermentation takes 3 to 10 days, but this could take more time depending on the sugar content and temperature of your house.

4. Your fermentation station is too cold.
Fermentation slows down dramatically when the environment is cold. Ensure your kombucha bottles are somewhere relatively warm (68-78°F). For the winter months, this might mean investing in kombucha heating pads, or finding a warm area in your house (e.g. above the fridge, by a heater, or in the laundry room). Read more on ideal kombucha temperatures here.

5. You’re leaving too much air in the bottles.
It’s important to leave some head space (empty space) at the top of the bottles before sealing, which will act as a buffer for the pressure (and in turn prevent explosions). With that said, if you leave too much head space, the CO2 simply stays in the air inside the bottle rather than going into the kombucha, resulting in less fizz. Aim for about 1 to 2 inches of head space (this entirely depends on the bottle shape and size, so you may need to adjust as you settle into a fermentation routine).

6. You’re not stirring the kombucha before bottling.
If you’re pouring the kombucha straight from the fermentation jug into the bottles (and especially if you’re using a spigot, like in continuous brewing), then the bacteria and yeast are not being evenly distributed into the bottles. Be sure to give your kombucha a stir before bottling so that every jar can be equally full of that live yeast and bacteria power! This also mixes oxygen into the kombucha, which helps to stimulate the process of carbonation.

7. You’re filtering the kombucha before bottling.
By all means, filter the gunk out of the kombucha after the second fermentation, but not before! You want to get all those brown stringy bits (the yeast!) into your second fermentation bottles as well. These will do wonders for the carbonation and fizz.

8. Your tea isn’t strong enough.
It could be that your first fermentation brew just isn’t strong enough. Either add a few more bags of tea, or let the tea steep for longer to infuse your brew with more “food” for the bacteria and yeast.

9. You’re not adding fruit or sugar.
Adding mashed fruits, juices, sugar, or honey not only add flavor, but they are instrumental in carbonating your kombucha. They act as “food” sparking the reaction that creates carbonation. (Pro tip: for maximum fizz, add ginger!) See our favorite kombucha flavors here!

10. You’re burping the bottles too much.
I get it, the idea of a bottle exploding is a little scary (and cleaning up the mess that results? even more so). But if you’re burping your bottles daily to avoid potential catastrophe, you may be doing a disservice to your carbonation. Try holding off on burping your second fermentation bottles for 2 or 3 days if you’re having issues with kombucha not carbonating. (Worried about explosions? Store them in a cooler to contain the potential mess!)

141 thoughts on “Why Isn’t My Kombucha Fizzy? 10 Ways to Fix Flat Kombucha!”

  1. Going into F2 I removed SCOBY and then had to put everything for an emergency. The next day I bottled the Buch even though I didn’t put my Scoby back in…I’m wondering if I screwed the whole batch…I also used quart mason jars with plastic lids and now after reading I am wondering if I just fouled up the whole operation. Please help.

    • I don’t think anything would have been that damaged in such a short amount of time! Just pop the SCOBY back in an F1 and bottle the rest. It’ll be fine!

  2. Hi, Have you ever used a fruit cordial as your “food” for second fermentation? I used it once a long time ago (lemon I think) and it worked perfectly, but when I bought a bottle recently and tried it with my kombucha it didn’t fizz at all! Any ideas why?

  3. This has been a great post for figuring out how to get good fizz. Should the SCOBY be stored in the fridge or at room temp? When I was given the SCOBY it came from the fridge so I’ve been putting it back in after F1. Could that lead to flat kombucha?

  4. We had the beer top type bottle and could not open and close. So that is out. Have been using screw top bottles. Will try a little honey in 2nd fermentation; can’t add a lot because of sugar problems. My favorite has become hibiscus ginger. If using flowers how long do I dry them before using in 1st fermentation? I put ginger in 2nd. TIA

  5. So, now I see that F2 in mason jars doesn’t produce fizz! The bottles I use have pretty long narrow necks (.75 liter limonade botttles), which makes it hard to use real fruit. Even blueberries get stuck in the funnel. Is it worth getting clamp top mason jars?

    • I haven’t tried the clamp tops so I can’t say for sure, but I think they would work better than the twist on tops! You could also try pureeing your fruit to fit in the bottles better 🙂

  6. Just getting started with this project and am finding some very helpful information on your site. Looked at a couple of flavor recipes and do not see amounts of the flavor ingredients listed for each bottle. I am very interested in making lemon ginger, but have no idea how much to use of each. Also, does ginger in dried powder form work or must it be fresh ? Thanks for your feedback.

    • Hi Gail! There are ingredient amounts listed for each recipe, but given that people use different sized bottles we can’t tell you how much per bottle. And you can use dried ginger! 😀

  7. I have not been stirring the first brew before bottling because the scoby usually floats around in the bottom. I pour out the kambucha, then as a last step, carefully pour the scoby into a mason jar (along with 3 cups of my previous brew) for storing. Wouldn’t stirring break up and damage the scoby?

  8. Great post Sarah! I’d like to get your thoughts on my somewhat odd (at least to me) carbonation issue. I did a 4ish day second ferment with a few separate fresh fruit additions: pureed strawberry + lime juice, pureed mango, and squeezed mandarin + rosemary. The strawberries I used were barely sweet, but to my surprise THAT was the one created the most carbonation (on a scale of 1 to 10, it was a 23). The mango had the smallest fizz pop when I opened it, and the squeezed mandarin had 0 carbonation. I would have guessed that the mango or mandarin would be the most carbonated due to the higher sugar content, but I was wayyyy wrong. Any thoughts? Thanks!

    • So strange, I would think the sugar content should make them all about equal! Is it possible there was more yeasty bits in the strawberry one?

  9. I have been doing kombucha for years THE SAME WAY and it always got fizzy and then, all of a sudden NO FIZZ. I can’t figure out what happened? I have never “stirred” the kombucha before bottling but I can try that. However, since I have never changed anything, I doubt that will help. I put my bottles on a heating pad in the winter (not wrapped around) but “sitting” on one. Could this be it? I am going to try ginger and see if that makes a difference…

    • It could be that it just needs a fresh addition of some outside kombucha (like unflavored store bought or from a friend). Perhaps the colony is just getting a little weak?

  10. Sarah, thank you SO much for all this handholding! A few questions: 1. I accidentally used all my f1 bucha in the f2 process and forgot to reserve some to keep my scoby in. So I threw like a quarter-cup of flavored bucha that I had already poured into f2 bottles (but hadn’t sealed or fermented yet), back into the scoby container. So it’s been through f1, and it’s flavored, but it didn’t go through f2. Is that ruination, both for being flavored and for being just a small amount of liquid? I don’t want to start my second batch with a defective scoby and starter liquid.

    2. Where did the word scoby come from and how do you pronounce it?

    3. On the straining/burping sequence. I love max fizz. But when I strained the finished product into a new bottle, releasing the fizz and the gunkies and putting the strained buch into the fridge, the next time I opened the bottle, it was flat. I saw the other questioners asking about this and it seems like there isn’t a great answer that retains fizz well AND gets the gunkies out. Is the solution to let it sit at room temp AFTER you strain and re-build carbonation and THEN refrigerate? Also, when I first started buying bucha, I noticed that ingredients often said “juice” of some fruit rather than the actual whole fruit mashed up. Now I’m wondering if these retailers knew what we’re all learning – that people don’t like the gunkies, so just putting in juice instead the whole fruit creates the texture and consistency that we all came to love when we were buying and not brewing. What if we blended up the fruit and truly juiced it instead of mashing? I don’t know how that would work with ginger, which is one of my must-haves. Thoughts?

    • Hi Katy! It may be okay, but I would probably get some unflavored kombucha in there too to acidify it and prevent mold.

      2. Here’s some info on what a SCOBY is (pronounced skow-bee).

      3. Yep exactly. Straining is always going to remove fermentation, so either strain it directly into your glass right before drinking it, or let it sit out at room temp for a while to recarbonate.

      And you can totally do juice! It works just about the same as mashed 😀

  11. I used Brown Sugar ! I think thats why this batch has been slow to make scobies and barely any carbonatiin during the second .. I think i will add some sugar in second fermentation.. should I add a couple of tabkespoons of brew of tea and sugar to 2nd fermentation ? Thanks

  12. I’ve been saving my bottles from my store-bought kombucha addiction. They are thick glass with plastic screw-on lids. Can I use those for bottling during the 2nd fermentation if I clean them really well first?

    • Yep those will work! Flip top fermentation bottles are usually best for carbonation, but those bottles have worked well in my experience.

  13. I’m new to Kombucha and I have never had a problem with my 1st fermentation, When I did my second fermentation, it had a lot of carbonation, Then I strained it and put it in the fridge to get cold, days later it was flat when I tried it. I can drink it cold or hot, I prefer it cold. do I need to strain after 2nd fermentation let it stand again room temp to get the carbonation to build up again, then put it in the fridge? and when you take a fully carbonated Kombucha put it in the fridge will it still keep the carbonation? I’m so confused on second fermentation!

    • Try straining it riiiight before serving (I like to pour the refrigerated, unstrained kombucha through a small strainer and right into my glass. But if it loses carbonation in the fridge, you can always set it back at room temp for a few hours to recarbonate!

    • Carbonation is actually temperature dependent. If you cool it it actually changes the amount of available carbon dioxide vs warm (room temperature). If you check with some beer making sites you will find calculators that will tell you how much sugar to add for how much carbonation at a given temperature

  14. Okay, so I’m pretty sure I bottled up my kombucha before it was done truly fermenting the first time. A) my SCOBY growth was wafer thin and B) there were no bubbles at time of bottling. It’s been in bottles for about three days now- normally the time when I would expect to see more bubbles and when I would stick it in the fridge. Is it okay to just return it as is from the bottles to the brewing jar along with the SCOBY (who has been in its hotel) and pretend like I’m starting from scratch?

  15. So now I’m really confused about first, second and third fermentations. The class I took had us transfer our ph tested/ correct (first fermentation)brew into smaller bottles and add our fruit. Then let bottles sit for 24 hours, burping occasionally, then refrigerate and begin consuming.
    So what am I missing with a 2nd fermentation, before straining? My brews have been good, tasty…but only slightly fizzy. I strain as I bottle as I’m just not into having the strands floating in the ones I give to friends, etc. Am I missing a crucial step? Do I need more/different bottles for the 2nd fermentation? Thanks…i do enjoy the site!

    • Sounds like you’re doing everything right! Maybe for the fizzy problem you can strain right before serving. That way the yeast gooeys still get in there but your friends don’t have them in their final brew?

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