If you are thinking about a kombucha second fermentation, then you must have already gone through a first fermentation cycle. If you still haven’t, try reading this article on the steps for kombucha brewing and the first fermentation.
When making kombucha, you will have to undergo two rounds of fermentation. In the first round, you are fermenting the sweet tea so that the kombucha is full of bacteria and yeast, which gives it its unique flavor and health properties. However, after this first fermentation round, your kombucha is unflavored and flat.
What is the second fermentation?
The second fermentation is the process in which your kombucha will get the flavor and also the carbonation. This occurs when you flavor the drink, place it in a sealed container, and trap the carbonation inside. For some, the second fermentation may be ready at the two-day mark, but for others, more carbonation is better, so it can take 5 days or more.
This is the process of forcing carbonation into a bottle, similar to what happens in beer and champagne. Because there is sugar, the yeast in your brew will eat it up, and convert it to carbon dioxide, resulting in the fizzy texture and flavor you like. In most cases, the sugar comes from the fruit that is added to the kombucha.
Here are the 6 steps to follow for your kombucha second fermentation:
Step #1: Add your fruit to the bottles
A good amount of pureed fruit or juice to add to your 16-ounce bottle is about ¼ cup. For the most part, expect to get around six to seven bottles. If you are not sure what flavors to use, the best choice usually includes fresh fruit or fruit juices. You can use more or less than the amount above, as it is really up to your preference in terms of flavor.
You need sugar for your kombucha to get carbonation, which is why fruit is almost always the right choice. By giving the drink some juice or pureed fruit, you are essentially feeding the yeast that will give off carbon dioxide and turn your kombucha into a carbonated beverage.
Step #2: Remove the SCOBY and two cups of kombucha
Once you have flavored the bottles, it is time to remove the SCOBY along with two cups of kombucha from your brewing jar. Remember to save the SCOBY and kombucha together, as it will be the starter tea and SCOBY that you can use in a future kombucha brewing adventure. You can also keep a SCOBY hotel, which you can read about here.
Otherwise, place the SCOBY and the tea in a bowl and use it within a day or two for your new kombucha brewing.
Step #3: Stir your remaining kombucha
While some people don’t know this, stirring the remaining kombucha into your brewing vessel is essential to distribute the yeast and bacteria equally in the liquid. Don’t skip this step, as it will ensure that your carbonation is equal in all the bottles.
Step #4: Pour the kombucha into the bottles
You can use a funnel to pour the kombucha into your bottles, but be sure to leave about one inch of headspace at the top. Dry the top of the bottles and make sure the lids are also dry. Seal the bottles tightly, making sure there is no airflow coming in or out.
Step #5: Allow your bottles to ferment for an extra couple of days or more
Now that your kombucha is ready, allow for it to ferment at room temperature for an extra couple of days. While you can check at the two-day mark, you may want to give them a few more days, as it will get more carbonation.
Be careful, though, if your bottles and lids are not of good quality, there may be over carbonation. This phenomenon can lead to explosions, especially if your fruit purees are strong.
You can place your bottles in a dark room or cupboard on their own, especially so you can avoid a mess in the rare case that your kombucha over-carbonates.
Step #6: Move your bottles to the fridge
When your bottles have reached the desired level of carbonation, it is best to move them to the refrigerator. After they have been there for a few hours, you can open the bottles and test them. The cold is a good way to keep the carbon dioxide within the liquid, preventing a mess when you open the bottle.
What if I want more fizziness?
Now that you know how to carry out the second fermentation, you may also find that the process is not set in stone. For some flavored kombucha, the second fermentation will last only two days. In other cases, the whole process may take up to a week. It depends on what level of fizziness you want, so make sure to check and chill your bottles once they are ready.