Simple Sustainable Sovereign

The Process of Kombucha Brewing

Making kombucha is a two step process, the first step being the primary ferment which involves a SCOBY and sweet tea. Once the kombucha has reached an appropriate level of fermentation in the primary ferment, it is time to move on to the secondary ferment, which entails bottling and flavoring the kombucha. This post will address the secondary fermentation process; for more information on getting started with kombucha and primary fermentation, check out my previous blog post “How to Make Kombucha”.

If you have gotten started with kombucha brewing and completed your initial ferment, then you are ready to move on to the next portion of the process, the secondary ferment.

What is the Secondary Ferment?

The secondary ferment of kombucha occurs once the kombucha liquid is bottled with some type of sugar, which both flavors the kombucha and feeds the bacteria and yeast present in the kombucha liquid, creating a tasty carbonated drink.

How does kombucha become carbonated?

Carbonation occurs because as the bacteria and yeast break down glucose (sugar), they convert it into carbon dioxide, and in an environment absent of air (a sealed bottle) the carbon dioxide is unable to escape which results in the liquid becoming carbonated.

What kind of sugar is used in this process?

Fruit, either whole, juiced, or pureed, is generally the source of sugar used in this process, as is adds flavor provides the natural glucose content needed to propel the creation of carbonation.

Flavoring Kombucha

One of the most fun parts of making kombucha is experimenting with different flavors. The sky is the limit here, and you can be as basic or creative as you would like. Most of the time, no matter the flavor, the kombucha will taste delicious.

Kombucha Flavoring Ideas

Use what you have on hand, what’s in your freezer, or what’s fresh at the farmer’s market. The options are really endless!

Things to Know Before Bottling

Bottle Types

The type of bottle you use for your kombucha is important for two reasons. The first is that if your bottles do not have a tight seal, the carbon dioxide will be able to escape which will leave your finished product with significantly less fizz. Additionally, you must use bottles that are able to withstand the pressure of fermentation, as if they cannot take this pressure it could result in the creation of a glass bottle kombucha bomb (which is just as terrifying as it sounds).

So, opt for pressure rated flip top bottles specifically made for home brewing. You can find these at a local homebrew store or online, such as these ones from amazon (affiliate link).

Fermentation Rate

The length of time that is required for the secondary ferment to occur varies depending on a variety of factors. These include the temperature of your environment, the sugar content of the flavoring agent, how the flavoring agent is prepared, and the strength of your kombucha liquid following your primary ferment.

Temperature:

The bacteria and yeast in kombucha are more active in warmer environments and slow down in cooler temperatures. In a warmer environment, bottles kombucha may be super fizzy and ready to go after 2-3 days, but in cooler settings it may take up to a week or beyond to reach the desired carbonation level.

Sugar levels:

Some fruits and vegetables naturally contain higher glucose levels than others, which will result in more activity and quicker fermentation rates. Mangoes, pears, and watermelon, for example, are much higher in sugar than fruits like raspberries or strawberries. If you are using a fruit with a lower sugar level, or perhaps making plain kombucha, your kombucha will likely take longer to build carbonation.

Flavor agent preparation:

The way in which you prepare your kombucha flavoring agent will also impact the rate at which your kombucha builds fermentation. If your flavoring additions are pureed or in the form of juice, the sugars are much more readily available to be accessed by the bacteria and yeast than when using fruit cut into chunks or whole berries. I prefer to puree whatever I am using to add flavor by blending it with a little bit kombucha liquid if needed.

Kombucha liquid strength:

It is important to wait until your kombucha has reached an appropriate level of fermentation in the initial ferment before bottling. Following the initial ferment, the kombucha liquid should taste sour and tangy, with just a slight bit of sweetness. If it is still very sweet it will take a long time to build carbonation, or may not get very carbonated at all.

Ratios

The ratio of kombucha liquid to flavoring agent is an important factor in creating a delicious, well-carbonated beverage. The recommended ratio is about 10-15% fruit (whole, juice, or puree) to 85-90% kombucha liquid. So, if you are using 16 oz bottles you will need about 1-2 oz per bottle, and 3-4 oz for 32 oz bottles. If you puree your fruit with a little bit of kombucha, you will want to use closer to 15% puree, but if you are using straight fruit you can stay closer to 10%. I am never very scientific about it and generally just eyeball the amount of puree I add, but if you are seeking very consistent results you will want to follow these guidelines.

Burping

As carbonation builds, kombucha builds pressure. To gauge the level of fermentation and to avoid any explosions, you will need to “burp” your bottles periodically. How long you should wait before burping your bottles depends on the factors listed above in the Fermentation Rate section, if you are using fruits high in sugar or have a very warm environment, you can burp your bottles 1-2 days after bottling, but if it is cooler or you used flavoring agents lower in sugar, you may want to wait 3-5 days before burping for the first time.

To burp your bottles, slowly open the top of one bottle while holding it shut with the other hand. Slowly allow the pressure to escape, gauging how forcefully the air leaks out. After allowing a bit of air to escape, close tightly again. If there is not much pressure, leave them to sit for 2-5 more days before burping again. If they are very pressurized and carbonated, leave to sit for another day so that the carbonation you just released can build up once again, then place the bottles in the fridge without burping again. You do not want to burp your bottles too frequently or immediately before placing them in the fridge, as this will allow all of the gas to escape and result in less carbonation.

How to Bottle and Flavor Kombucha

Ingredients & Tools:

• 14-15 oz Kombucha Liquid per Bottle – This is kombucha that has already undergone a primary ferment. Learn more in my previous post “How to Make Kombucha“.
• 1-2 oz Fruit Juice or Puree per Bottle
• 12- 16 oz Bottles – Flip top and pressure rated.
• Funnel – Optional but helpful.
• Strainer – Optional.

Directions

1. Prepare: Begin by ensuring that your kombucha bottles are clean and have no cracks. Taste your kombucha from the primary ferment to make sure it has reached a good level of fermentation. It should taste tart and slightly vinegary with just a hint of sweetness.
2. Puree Fruit: If using fruit puree, blend your fruit of choice in a blender, either alone or with a little kombucha liquid if needed to help it blend.
3. Fill Bottles: Pour 1-2 oz of puree or juice into each bottle using the funnel. Using the funnel again, fill the bottles up to the neck with 14-15 oz kombucha liquid, leaving about 2 inches of headspace at the top.
4. Ferment: Close lids and leave to ferment on the counter.
5. Burping: After 1-5 days, gently burp your bottles to gauge the amount of carbonation and allow some gas to escape. If they have reached your desired level of carbonation, place them in the fridge to slow fermentation. If they are not yet very carbonated, wait 2-5 more days before burping again.
6. Enjoy! You may desire to use a strainer to remove any fruit pulp, seeds, or SCOBY parts before drinking.

Notes:

The amount of time that your secondary ferment takes to build carbonation will vary depending on the temperature of your environment, the sugar content of the fruit you use, whether you use juice or puree, and the strength of your kombucha liquid following your primary ferment.

Your bottled kombucha may begin to grow small SCOBYs. This is normal and you can either swallow them or remove them before drinking.

What is your favorite kombucha flavor? Let me know in the comments below!

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