How to make kombucha at home: the complete guide

Kombucha is a tangy, slightly fizzy drink made from fermented tea. You can brew it at home with just a handful of ingredients, and once you have a starter you can keep making it for the rest of your life. In this article you will learn the process step by step: with a SCOBY, without one, and how to create your own flavour combinations.

Kombucha is a fermented tea drink, probably originating somewhere in East Asia. The exact origins are unknown. You make it by fermenting sweet tea with a combination of bacteria and yeasts. That partnership is called a SCOBY: Symbiotic Culture of Bacteria and Yeast. The lactic acid bacteria, acetic acid bacteria and yeasts convert the sugar into acids, a small amount of alcohol and carbon dioxide. The result is a drink that tastes pleasantly tart, has a light fizz, and lends itself to endless variation.

During fermentation, a jelly-like disc of cellulose forms on the surface. Almost everyone calls this disc “the SCOBY”, but technically it is called the pellicle or biofilm. It is also affectionately known as “the mother”. The real SCOBY is the whole thing: the liquid and the pellicle together. When we refer to “SCOBY” in this article, we mean exactly that: the liquid plus the pellicle, together forming the living starter you need.

This is the standard method and by far the most reliable way to get started.

1. Boil water and brew tea (5-7 grams per litre). Dissolve 50-100 grams of sugar per litre in the hot tea.
2. Let the sweet tea cool completely to room temperature. Tea that is too hot will kill the microorganisms in your starter. Make sure your glass jar is clean. Rinse it thoroughly with hot water beforehand.
3. Pour the cooled tea into the jar. Add roughly 10% mature kombucha (so 100 ml per litre) along with the pellicle.
4. Cover the jar with a cloth and secure it with a rubber band. Do not use a lid: the fermentation needs oxygen.
5. Place the jar somewhere at room temperature or slightly warmer (20-30°C), out of direct sunlight. Higher temperatures speed up fermentation and produce a more sour result.
6. Let it ferment for 7 to 14 days. After a week, taste regularly with a clean spoon. Pleasantly tart and no longer too sweet? Then it is ready.
   Optional: measure the pH. It should be below 4.6. Ideal for kombucha is 2.5 to 3.5.
7. Always save at least 10% of your kombucha along with the pellicle for your next brew.

Want to know more about safe brewing, recognising mould and common problems? Read Is kombucha safe to drink?

You can order a tested, organic kombucha SCOBY from us, guaranteed free of pathogens.

Once your base kombucha is ready, you can do a second fermentation. This is also called F2. During F2, you add flavourings and create carbonation. Ginger kombucha is the most popular variation, but the possibilities are wide open.

Example: ginger kombucha

1. Pour your finished kombucha (without the pellicle) into a pressure-resistant bottle.
2. Add a few slices of fresh ginger, and optionally a slice of lemon.
3. Optionally add a teaspoon of sugar.
4. Seal the bottle tightly.
5. Leave for 1-7 days at room temperature. The yeasts convert the remaining sugar into carbon dioxide.
6. Then put the bottle in the fridge to stabilise the pressure. Open carefully, preferably over the sink.

Note: the more fruit or pulp you add, the more pressure can build up in the bottle. Be careful with that. Other popular combinations: blueberry-ginger, cranberry-orange, fig with rosemary, or strawberry-pineapple. Looking for more ideas? Read 5 surprising things you can do with kombucha.