If you read our previous post on how to make kombucha, you know that kombucha is a two-part process consisting of primary and secondary fermentation. The primary fermentation is where kombucha is made, but when it’s finished, it will be unflavored and still (flat). The secondary fermentation, or 2F, is when kombucha is bottled, flavored, and carbonated. In this post, we’re taking the finished kombucha from the primary fermentation and bottling it up, flavoring, and carbonating. It’s this step that really brings the kombucha to life.
Bottling your kombucha serves a few purposes. First, bottling is required to create carbonated kombucha. When using proper bottles, this process provides an environment where carbonation can build up but not escape. When co2 cannot escape from the bottles, it forces the co2 back into your kombucha, which in turn, carbonates it. Carbonation adds so much to the finished product in terms of brightness, texture, and flavor. In addition to carbonation, bottling is the step where you add flavor, more on this later. Bottling also provides secure storage to place in the fridge neatly or to travel if you want to bring your kombucha on the go or to share with a friend.
Bottles with lids that are designed to hold pressure! When choosing kombucha second fermentation bottles, the most important thing is that the lids are designed to hold the pressure pressure of fermentation. There are a variety of kombucha bottles that will provide an airtight seal, but aren’t designed to hold the building pressure of carbonation. So make sure the bottles and lids you choose are designed for this task, otherwise, you will struggle with carbonation. What I recommend is either using swing-top bottles or stout bottles; both of these are made for fermentation and have lids designed to hold pressure.
Bottling occurs after the primary fermentation has finished. The first fermentation is complete when the pH is between 2.5 and 3.5, and you have achieved your preferred flavor balance of sweet and tart. This process typically takes about 7-21 days, depending on temperature. At this point, we have finished kombucha, but again it will be plain and flat. If you prefer an uncarbonated, plain kombucha, then simply bottle and place in the refrigerator to cool before drinking. If you prefer to flavor and carbonate your kombucha, you’ll need a kombucha second fermentation in the bottles.
To get carbonation in our kombucha, we need to feed the yeast sugar in a closed environment like a bottle. Adding sugar, fruit, or juice to the bottles during the 2nd ferment will feed the yeast. As the yeast begins to consume the sugars, they will create co2. In the primary fermentation, the co2 escapes through the opening in your brewing vessel. Allowing the co2 to release is why you will never have carbonation after the primary fermentation. Now, since this time around we have an sealed chamber, the co2 has nowhere to go. Now, the co2 will build up inside the bottle, which in turn forces or dissolves the co2 into your kombucha, which carbonates it. Carbonation and flavoring go hand in hand. We can get creative when adding sugars to carbonate. If we want plain kombucha, add cane sugar. If we would like peach kombucha, add sugar i.e., fresh peaches or peach juice. Bonus – the fruit or fruit juice both flavors and provides the sugar needed for your yeast to carbonate. After adding sugar/flavorings to the bottles, we’ll let them sit out, tightly capped, for 2-10 days at room temperature (75-85°F). Don’t forget to burp your bottles!
As you may have noticed, we are capturing carbonation in a glass bottle. In other words, the co2 is building pressure inside a sealed container. Burping kombucha is designed to alleviates excess pressure as this can get ugly if we allow this to build for too long. An essential step in this process is to “burp” your bottles after one day. This is done to check on how the pressure is building and releases any excess co2. To burp, pop open the cap and then put it back on, releasing excessive built-up CO2. If you don’t do this, you may end up with a geyser, or even worse; you may wake up at 4:30 AM to the sound of the infamous “bottle bomb” and waterfalls of kombucha dripping down your cabinets (I speak from experience).
If you burp after a day and not much is happening, stop burping. We need to keep the caps on for a few more days to allow the carbonation to build up, assess the temperature and make adjustments as necessary.
When it comes to bottling your kombucha, I have a few words of advice:
For one gallon of kombucha, you’ll need 7, 16 oz bottles.
Are you not getting carbonation built up even after seven days? Check out this post on how to get fizzy kombucha for some tips.
