Sustainability Journal – Kombucha (fermented tea)

What is Kombucha?

It is a fermented tea (black, green tea or white tea i.e. Camellia sinensis) drink that works as probiotic, which means that it’s full of live microorganisms intended to provide health benefits when consumed, generally by improving or restoring the gut flora.
The result is an acidic, sweet, bit alcoholic and effervescent drink.


What is SCOBY?
Acronym for Symbiotic Culture of Bacteria and Yeast which is very auto-explained. It is the sponge-like thing you will see growing in your kombucha.


Note that a lot of what is said here can be made in a different way by other persons. Just get informed, compare and choose what you think it’s the best for you.


– Don’t put metal objects in contact with the kombucha, they may kill the microorganisms in the kombucha.

– Don’t wash your hands with anti-bacterial detergent before handling the SCOBY, use only hot water and normal soap.

– Store SCOBY in glass containers instead of metal or plastic ones. Metal can have an adverse reaction with the acidic kombucha, while plastic may absorb the bacteria.

– It is needed a minimum of 10% starter tea for the total volume of kombucha being made (Example: 0,1 litre of starter tea, not counting the SCOBY for 1 litre of new tea).



1. Boil water for some minutes
– It’s nice to use filtered/spring water because chlorine can harm the nice bacteria and yeast that will create the kombucha.
– Minerals in water may affect the flavor of kombucha

2. Remove the water from the heat and put the tea bags/tea infuser there for 15 minutes and then remove it
– More less 5 bags/3L (or the equivalent for bulk tea)

3. Pour sugar into the tea and stir it until it dissolves
– 50 – 60 g/L of tea

4. Wait until the tea reach room temperature (< 29ºC)
– SCOBY is sensitive to hot temperatures
– You can speed the process with an ice/water bath
– The tea should not take more than 4 hours to cool because it can get pathogens

5. Remove the SCOBY from the starter liquid, with your hands, add it to the tea and cover it with a piece of cloth and a rubber band
– The cloth should block bugs but allow air to circulate


6. Leave the jar in a place without direct sunlight with temperatures between 20 to 29ºC for 7-14 days
– Choose a place with air circulation

7. Taste the tea after 7 days to see if it’s good
– The smell of the kombucha, SCOBY, bubbles and yeast (like clouds) appearing should be enough to see if it’s ready to be drinked

8. If it’s good, separate the liquid from the SCOBY and you have two choices:
8.1. Put it in the fridge and drink it the way it is
8.2. For carbonation, add some natural juice and put it in closed bottles for 1-3 days until you have enough bubbles
– Room temperature and out of direct sunlight
– Around 1/2 cup of juice for 1 liter of kombucha
– When you have enough bubbles, put the bottle in the fridge (just open when the kombucha is completely cold
– Bottles like the ones in the picture below are the best for that purpose


9. You can repeat the process with the SCOBY with fresh and sweet tea



– When getting your kombucha from someone, ask if the person is using vinegar on the process. If yes, I would not take from that kombucha, because it’s possible that the person is producing vinegar and not kombucha.

– For starting a kombucha, you can get starter liquid and SCOBY from a friend, get from something like olx or even create your own from a store bought unflavoured kombucha (not the best environmentally but better than to buy a new bottle every time you want to drink kombucha).

– Brown sugar creates better kombucha, because the white sugar doesn’t have minerals and can contain chemicals that can harm your kombucha.

– Choose only sugar from the sugar cane.

– Pay attention to your kombucha and when something change, search for it.

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