Drinking kombucha is great, but making it is even better. Here is how it's done!
Steps for starting your own kombucha:
1. Get a SCOBY and starter liquid (=raw kombucha). There are numerous ways to obtain your own SCOBY, like getting them from a friend that already has one, or buying them via platforms like Marktplaats. When in stock, The Kombucha Masters also provides SCOBY’s for the curious home-brewers (get in contact if you are interested!).
2. Make tea with sugar. White, green, black; it all works for making kombucha, as long as you use the leaves from the tea plant (Camellia sinensis). The different kinds of tea will result in different kinds of flavour and colour in the final kombucha. Use about 4 to 8 grams of sugar per liter of tea. The sugar that you use also will be of influence on the brew. White beet sugar or cane sugar will all do. Do not use sugar replacers for the initial fermentation, like honey or stevia; sucrose is needed as food for the yeasts. You can play a bit with the amount of sugar you add, but it is best to remain within a range of 50 to 100 gr per liter of tea.
Add the chosen amount of sugar to the tea and steer untill it is all dissolved. Let the tea cool down to <40°C. The SCOBY contains living micro-organisms and you don’t want to kill them with adding boiling water. You can also just add some cold water after the tea has been in for a while. When you can touch the tea with your hand, it’s also fine for your colony of bacteria and yeasts.
3. Add sugared tea to the SCOBY and starting liquid. Get a jar that you would like to use for making your kombucha (preferably >1L, but it’s up to you how much you want to make per cycle). Make sure that the starter liquid and sugared tea are in a ratio of around 1:10. In this way the pH becomes a bit lower, preventing other microbes to start living in the sugared liquid. If you only have the SCOBY and no kombucha, then some vinegar can also be used as a starter.
4. Close off your jar. This can be done with a breathable fabric and a rubber band to close off the jar. The fermentation relies on available oxygen, but you do not want any fruit flies or other interested organisms to drop into your jar.
5. Let it ferment for 10 to 20 days. In this period, the actual fermentation happens. The sugared tea will be transformed in a refreshing, sour-sweet drink (see 'What is kombucha?' for the exact process!). Depending on the environment temperature of your jar, and on how sweet or sour you like your kombucha, the fermentation time can differ. You can even make vinegar out of it, if you let it ferment for long enough (> 20 days). When you are satisfied with the taste of your brew, you can take out 9/10th of the liquid into a bottle, leaving the SCOBY in the first jar. The other 1/10th you left can be used as a starter for you next batch.
6. Keep your home-made kombucha bottle cold and enjoy! When you place the bottle in the fridge, the fermenation stops and the flavour is maintained. Also, in this way the pressure in the bottle does not build-up (something that you have to be aware of when it is not stored cold; you wouldn't be the first one to experience the shaked-champagne-effect after opening your kombucha).
You can dilute your brew with some water if you find the taste too strong (I like my kombucha best with half water, half kombucha). For some extra flavour options, you can add some juice, fruit, honey, herbs, or whatever you want to try out to your bottle of kombucha and do a second fermentation. This means that after adding the flavour to the bottle, you keep it for another ~2 days in room temperature (let you bottle 'burb' every day to prevent pressure builing up). In this way, your kombucha will turn into a carbonated drink with extra flavour. The Kombucha Masters do the second fermentation with ginger, lemon, hibiscus and elderflower (and more flavours coming soon!).