Having your kombucha pop with fizz is a sign you’ve become a master kombucha brewer.
Most beginners really struggle with getting the right amount of carbonation. The good news is, the fizzy kombucha you’ve been searching for is only one brew away!
There are many different factors that determine the carbonation level in your kombucha.
I’ll talk about all of them below and where you might be going wrong.
Let’s get carbonated!
Where Does The Fizz Come From?
Before we get into how to fix your flat kombucha it’s a good idea to know where the carbonation is coming from in the first place.
Remember how kombucha is a two-step process?
The yeast produces the alcohol which is then digested by the bacteria. The process of producing the alcohol is called fermentation.
Fermentation occurs in anaerobic conditions. In other words, no oxygen.
This is exactly why we do the second ferment. During fermentation, CO2 is produced (along with alcohol) which is what gives kombucha the fizzy taste.
By cutting off the oxygen supply in our flip-top bottles we essentially force the yeast into fermentation which produces both the flavor and the fizz.
It’s as simple as that!
How To Improve Your Carbonation
Now that we understand the process behind producing the CO2 we can learn how to improve it.
You’ll be happy to learn that you likely won’t have to make any drastic changes to your brewing routine. After a few tweaks, you will be enjoying the bubbly kombucha you’ve been craving.
1. Use More Sugar
If you’ve been skimping out on the sugar you may be starving your yeast. If the yeast doesn’t have enough sugar to digest they won’t be able to produce the right amount of C02.
No matter how long you let your bottles sit on the counter they won’t produce more fizz.
I recommend using a minimum of 1 cup of sugar per gallon of kombucha.
Anything less and you will have a hard time getting high levels of carbonation.
2. Use Fruits With Natural Sugars
If someone has been struggling to get carbonation in their kombucha I usually tell them to try this recipe:
- 1/3 cup fresh pineapple (chopped)
- 1 teaspoon of chopped ginger
Pineapples are chaulked full of natural sugars. This combination tends to be very explosive (sometimes literally) when it comes to kombucha.
If you’ve been using the right amount of sugar and you still can’t get the carbonation you’re looking for then I recommend you try this as your next step.
You don’t always have to use pineapple (it’s just what I find works almost every time.) You can also use strawberries or mango. Both with add a punch of fizz to your brew.
3. Use Fruit Juice or Fruit Puree
If you still aren’t getting fizz the next step is to try a more concentrated form of sugar. Either use fruit juice from a bottle or create your own with a juicer.
If you don’t have a juicer then just puree your fruit in your food processor or blender.
I like using a combination of fruits (mango, pineapple, strawberries etc.) But feel free to experiment.
Also, make sure you are putting at least 1/4 cup of fruit juice (or puree) into each bottle. If you are still experimenting, it may be a good idea to vary the amount of fruit you put into each bottle so you can see the difference it makes in carbonation.
4. Use The Right Type Of Bottle
Another common mistake I see people making is they are using the wrong type of bottle. Most people get started by reusing their old store-bought kombucha bottles.
Unfortunately, after you crack them open the seals on these bottles are not airtight.
While you may think they are tight, your precious CO2 is leaking out without you noticing.
Almost every kombucha brewer I know uses flip-top brewing bottles. You can find my recommendation here.
You will also want to only use bottles that are thick enough to handle all the carbonation you will be building. You can’t go wrong with my recommendation above.
5. Get The Timing Right
Another common beginner mistake is getting the fermentation lengths wrong. Remember, you are trying to find the right balance between sugar and acid during both the first and second ferments.
If you leave your first ferment too long the yeast will devour all of the sugar and you won’t have much left over in the bottle for your second ferment.
This usually results in kombucha that is slightly too acidic and also flat.
I recommend leaving your first ferment for at least 7 days at the right temperature (more on this below).
If you aren’t getting the right amount of carbonation you can consider cutting your first ferment short a day and increasing your second ferment by a day or two.
A short second ferment is usually the main culprit for a lack of fizz.
When people ask me how long they should leave the kombucha in the bottles on the counter I always tell them “as long as it takes.”
Some brews take longer than others. The best way to know how long to leave the brews is to test after 2 days. Slowly remove the flip-top cap and listen to how much pressure has built up.
If you don’t hear a hiss then leave them out for another day and check again.
If you still can’t get any CO2 after a 7-day second ferment that means you didn’t add enough sugar, or your kombucha culture is weak.
6. Brew At The Right Temperature
Brewing temperatures should be kept at a minimum 75°F at all times. I prefer to brew my kombucha between 75 and 80°F.
This includes both the first ferment and the second!
This is another common mistake I see people making. They heat their first ferment but forget about the second.
Kombucha heaters designed for kombucha will allow you to heat both your main brewing vessel and your flip-top bottles.
Make sure you keep your brew at the optimal temperature to keep your yeast population happy.
7. Don’t Filter Your Yeast
You need the yeast in your bottles to produce the carbonation. This is why it’s a bad idea to filter out the yeast when bottling.
If you don’t know how to spot the yeast just look for the brow particulate at the bottom of your brewing vessel.
This is why it’s also a good idea to stir up your brewing vessel before you start bottling. This way all the yeast is evenly distributed amongst your bottles.
You can always filter your kombucha after the second ferment if you are hesitant to drink the yeast. However, I recommend you do as there are plenty of health benefits that come from the yeast.
That’s about it! If you’ve tried everything above and you still can’t get the carbonation just let me know if the comment section below!
Happy brewing!