Kombucha is a lightly fizzy, tart drink made by fermenting sweetened tea with a culture called a SCOBY. It is often sold as an alternative to soft drinks, but it tastes quite different from most of them. This guide explains what goes into it, where the fizz comes from, how it compares with a soft drink, and how it differs from other fermented teas.
What Kombucha Is Made From
Kombucha needs four basic things:
- Tea. Black or green tea is most common. The tea gives the drink its flavour and is the base the culture works on.
- Sugar. Plain white cane sugar is standard. The culture uses the sugar as food, and most of it is used up during fermentation. The sugar is not there to sweeten the finished drink.
- Water. Filtered or dechlorinated water is best.
- A culture. This is a SCOBY (short for symbiotic culture of bacteria and yeast), the rubbery disc that forms on the surface, plus some finished kombucha from a previous batch.
The SCOBY is the living part. It is not the drink itself, and it can float, sink or sit sideways during brewing.
How the Fizz Forms
Kombucha’s fizz comes from fermentation, not from added carbonation:
- The yeast in the culture consumes sugar and produces carbon dioxide.
- The bacteria convert some of the byproducts into acids, which give kombucha its sharp, tart taste.
- In an open jar, the carbon dioxide escapes. In a sealed bottle, it stays in the liquid and creates fizz.
This is why many home brewers bottle the finished drink for a few days. A little fruit juice or fruit adds more sugar for the yeast to feed on, which increases the fizz. How to make kombucha at home explains the bottling steps.
Kombucha vs a Soft Drink
Kombucha is not a like-for-like swap for a soft drink. The comparison below shows the main differences.
| Kombucha | Typical soft drink | |
|---|---|---|
| Base | Fermented sweet tea | Carbonated water with sugar or sweetener and flavourings |
| Fizz | From fermentation, and sometimes added carbonation in commercial versions | Added carbon dioxide |
| Taste | Tart, often with a sour edge and some sweetness | Sweet, with a more consistent flavour |
| Sugar | Some sugar remains, usually less than in the starting tea. The amount depends on fermentation time and the product. | Sugar or other sweeteners. Check the label. |
| Caffeine | Some, from the tea. The amount depends on the tea and the brew. | Varies. Many cola-style drinks contain caffeine. |
| Alcohol | A small trace from fermentation. Commercial labels often state a low figure. | Generally none |
| Live culture | Usually, unless the product is pasteurised | No |
Many people find the tart taste takes a few tries to enjoy. Kombucha is also less consistent than most soft drinks, because each batch and bottle can vary.
Other Fermented Teas
Kombucha is not the only fermented tea. Some brewers make fermented teas with honey, tea leaves and wild yeasts and bacteria, and without a SCOBY. These are a different process. The microbes come from the environment and the leaves, not from a started culture, so the results are less predictable. Some are fizzy, and honey often makes them sweeter.
A ginger bug, a starter made from ginger and sugar, is another fermented drink project that uses wild microbes. It is a separate method from kombucha.
For your first batch, a SCOBY-based kombucha recipe is the more reliable choice. If you try a wild-fermented tea later, use clean equipment and follow a tested recipe carefully.
Store-Bought or Homemade
Store-bought kombucha is widely available. The label can tell you a lot. Look for whether it says raw or unpasteurised, if you want live culture, and check the sugar and alcohol figures if they are listed. Commercial brands are generally made to a set process, so taste and fizz tend to be more consistent from bottle to bottle.
Homemade kombucha is less predictable. Taste, fizz and alcohol depend on your room temperature, the culture, how long it ferments and how you bottle it. A homemade batch can be more or less sweet, sharper or fizzier, and it can vary from one batch to the next. That is part of the appeal for many brewers.
Drinking It Sensibly
- Start small. Many guides suggest starting with a small glass, around 100 to 125 ml, and building up gradually while you see how you feel.
- Keep it cold. Refrigerate kombucha after bottling. Warm kombucha keeps fermenting and can become sharper and fizzier.
- Check the bottle. Throw out any kombucha with mould, a rotten smell or pressure that worries you. Is homemade kombucha safe to drink? lists the warning signs in more detail.
- Check with a professional first. People who are pregnant or breastfeeding, children, people with a weakened immune system, people with liver or kidney conditions, and people who avoid alcohol should check with a doctor before drinking kombucha.
Making Your Own
If you want to brew kombucha yourself, the basic process is simple: sweet tea, a SCOBY, some starter liquid and a clean glass jar, then a week or more of fermenting. The step-by-step recipe covers the amounts, timing and bottling.
FAQ
Is kombucha a soft drink?
It is sometimes sold as one, but it is a fermented drink rather than a carbonated soft drink. Its fizz comes from fermentation, and it tastes tarter than most soft drinks.
Does kombucha contain alcohol?
Yes, in small amounts. Fermentation produces a little alcohol. Commercial labels often state a low figure. Home batches can vary more. To keep yours as low as possible, see how to brew non-alcoholic kombucha.
Is kombucha sweet?
It is less sweet than the sweet tea it starts as, because the culture uses most of the sugar. How sweet it tastes depends on how long it has been fermenting.
Does kombucha contain caffeine?
Usually some, because it is made with tea. The amount depends on the tea used and how it was brewed, so there is no single figure that applies to every kombucha. If you notice a lift after a glass, why kombucha can make you feel buzzed explains the likely causes.