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Why Kombucha is Carbonated - Plus The Best Tips for Extra Carbonation

Kombucha is one of the many carbonated drinks in stores today, but the carbonation in kombucha is different than the carbonation in a drink such as Coca Cola or Lecroix. 

Kombucha is naturally carbonated during its 2nd fermentation. During this step of the brewing process, the kombucha is poured into air tight brewing bottles that are partially filled with some kind of sugary flavoring. The yeast and bacteria culture in the kombucha eat the sugar in the flavoring, producing carbon dioxide. And because the bottle is sealed, the CO2 that is produced builds up pressure inside and infuses into the kombucha, creating carbonation.

In this article, I'll talk about exactly why kombucha is carbonated, whether or not carbonation is healthy, and give you some great tips on how you can better carbonate your own kombucha. Lets get into it!

What is Kombucha?

Kombucha is a drink made from fermented tea. Because it is fermented, kombucha contains bacteria and is known as a probiotic. The drink has become quite popular in recent years due to its great taste and many health benefits such as improved digestion and gut health, detoxification, and immune system strengthening.

How Kombucha is Made

All booch begins as sweet tea. What turns this sweet tea into sweet and sour probiotic kombucha is a living culture of bacteria. This culture of bacteria, known as a SCOBY (Symbiotic Culture of Bacteria and Yeast), eats the sugar and caffeine from the sweet tea and produces acids, carbon dioxide, and alcohol.

Once it has eaten enough sugar to make the kombucha bitter tasting, the SCOBY is removed and the 1st fermentation is complete. At this point the kombucha can be drunk, but it's not carbonated or flavored yet.

The carbonation and flavor is added in a 2nd fermentation. During this stage, the kombucha is sealed in glass fermenting bottles that are filled with fruit, juice, or herbs for flavoring. 

Over the course of a few days, the kombucha in the bottles develops carbonation and flavor. It’s then refrigerated and ready to be drunk!

What is Carbonation and Where does it come from?

Carbonation is a naturally occurring or artificially induced process that happens when highly pressurized carbon dioxide is dissolved in a liquid. The carbon dioxide is then converted into carbonic acid, which is what gives carbonated drinks their “bite.” 

When you open a bottle of soda for example, the fizzing noise you hear is the carbon dioxide between the liquid and the cap being released.

And when you shake a bottle of soda, the carbon dioxide between the liquid and the cap is pushed back into the liquid, forming large bubbles that exert pressure on the soda and push it to the top of the bottle, causing it to explode when you open it.

Is Carbonation Healthy? 

There are a lot of rumors on the internet about the negative health effects of carbonated beverages. One common claim is that the carbonic acid that results from the carbonation process ruins the enamel on your teeth and causes kidney stones.

The truth is that there is no evidence out there to suggest that carbonation by itself is bad for you. The chemical that actually ruins tooth enamel and causes kidney stones is not carbonic acid but phosphoric acid.

Phosphoric acid is not a product of carbonation, but is actually an acid that is added to Coca Cola and Pepsi to give them a more tart flavor and prevent mold growth. The reason that carbonation itself is wrongfully associated with poor health is because when we think of carbonation we usually think of sugary and unhealthy sodas like these.

In one study, carbonated beverages showed strong potential to destroy enamel — but only if they contained sugar. In fact, a non-carbonated sweet beverage (Gatorade) was more harmful than a carbonated sugar-free drink (Diet Coke).

Actually, carbonation by itself, such as that in sparkling water, may provide some benefits. Studies suggest that carbonated water may improve swallowing ability, increase feelings of fullness, and reduce constipation.

Why Kombucha is Carbonated

The carbonation in kombucha occurs naturally during a part of the brewing process known as 2nd fermentation. We could drink kombucha after its 1st fermentation, but it wouldn’t be carbonated or flavored.

To carbonate and flavor it during the 2nd fermentation, the kombucha is bottled into airtight brewing bottles that are partially filled with some kind of fruit, juice, root, or herb for flavoring. A few of the flavors I really like to make when I home-brew kombucha are:

  • Cinnamon Pineapple

  • Mango Peach

  • Ginger Turmeric

  • Blueberry Vanilla

The added flavoring will make the kombucha taste good, but also serves as food for the yeast and bacteria culture to use for fermentation.

Although the large SCOBY isn’t in the brewing bottles, there are bits and pieces of the living bacteria culture in them that will eat the sugar in the flavoring and then produce carbon dioxide. Since the bottle is sealed air tight this carbon dioxide will build up pressure and eventually infuse into the kombucha, creating carbonation.

This process of 2nd fermentation usually takes 3-4 days, and once it's finished the kombucha is refrigerated and ready to be drunk!

How to Get More Carbonation in Your Kombucha

One of the biggest problems kombucha home-brewers have with their booch is not being able to get it carbonated enough. If your brews are ending up flat, here are a few quick fixes.

1. Increase the Length of 2nd Fermentation

During 2nd fermentation, the air tight bottles with kombucha and flavoring in them will sit at room temperature for about 3-4 days. After those 3-4 days the newly carbonated and flavored booch is placed in the fridge and ready to be drunk.

If, after refrigeration, you try your booch and it still isn’t carbonated enough, just move the bottles out of the fridge and back into room temperature for a few more days and they’ll develop more carbonation.

2. Use Good Quality Tightly Sealed Brewing Bottles

If you want good carbonation in your kombucha, I recommend using quality flip top brewing bottles.

Brewing bottles are bottles that seal air tight and can withstand pressure to make beer, kombucha, kefir, and other fermented drinks.

It is possible to use old kombucha bottles or even wine bottles for 2nd fermentation, but quality, tightly sealed brewing bottles will consistently hold pressure and create the best carbonation.

I got my set of 6 brewing bottles on Amazon. They've always created awesome carbonation in my booch and are super easy to use. They even come with a dry erase marker so you can write on them. I use it to keep track of the flavoring and the date they started fermenting. If you’re interested you can find them on Amazon here.

3. Add Extra Sugar

Sugar is what the yeast and bacteria use as food to produce the carbon dioxide required for carbonation, so if you don’t have enough sugar in your fermenting bottles, your booch will end up flat.

Fruit flavorings usually carbonate the best since they have a ton of sugar, but if you're using herbs or roots to flavor and your kombucha is ending up flat, try adding a few extra pinches of sugar or some sugar cubes to the bottles to give the yeast some more fuel.

4. Don't filter out the Bacteria or Yeast 

When transferring the kombucha from your large jar into the bottles for 2nd fermentation, it’s important not to filter out any of the yeast or bacteria clumps and strings.

Although they may look scary, the bacteria and yeast are needed in 2nd fermentation to produce the carbonation. If anything, you should be stirring up your booch to get more yeast and bacteria in your fermenting bottles to produce more carbonation.

5. Ferment in Warmer Temperatures

Warmer temperatures make the bacteria and yeast culture more active, therefore producing more CO2. This means that if you’re brewing in the winter months, your 2nd fermentation may take more time to develop carbonation.

If you can, try to place your brewing bottles somewhere in your house that is 70-75 degrees Fahrenheit. 

6. Don't Burp your Bottles

Burping is when you slightly open your bottles during second fermentation to allow some air and pressure to release. Although burping is recommended by some home-brewers, it’s actually unnecessary and counterproductive to the process of building carbonation.

People that recommend burping your kombucha claim that it prevents the bottle from exploding from too much pressure. But the truth is that if you invest in good quality brewing bottles, you won’t have to worry about any explosions.

All you’re doing by burping your bottles and removing built up pressure is making it harder for your kombucha to become carbonated.

Final Thoughts

Kombucha is carbonated as a result of the natural process of fermentation.

Carbonation provides no health risks and contrary to popular belief, does not destroy the enamel on your teeth or give you kidney stones.

If you’re home-brewing kombucha, you should be able to develop enough carbonation by using quality brewing bottles, a sugary flavoring, and giving the bacteria and yeast enough time to work. 

If you want to learn more about kombucha, how it relates to your health, and even how to brew it yourself, check out the rest of my website!

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