Making your own kombucha is super simple, and rewarding. I’m a big fan of the taste and it’s a great introduction to fermentation. The basics can be outlined in some simple steps
Aquire a SCOBY
Brew sweet tea or infusion (allow to cool!!!)
Introduce SCOBY (and the liquid it came in) in to tea, backslop with a little already made kombucha
Put it into a open vessel cover with cloth and Wait (approx 5-7 days)
*You have kombucha, you can enjoy this as is (cool it down first) or add it to a sealed bottle with some fresh fruit and juice for a second fermentation and carbonation.
So what are the players and why are they important:
WHAT IS A SCOBY?: SCOBY stands for Symbiotic, Culture of Bacteria and Yeast
A SCOBY takes on the appearance of a gelatinous, semi- transparent floating jellyfish. A healthy, happy SCOBY will sit on top of your kombucha like a weird, living, growing raft. Now the most important thing to know about a SCOBY is that it ‘eats’ sugars and transforms them first into alcohol and then into citric/acetic acid, which is what gives your kombucha its satisfying, crisp flavour. The process is continuous, cooperative fermentation, between a yeast(Saccharomyces cereviasse) and a bacteria (AAB: Acetic acid bacteria), your SCOBY requires air to thrive.
Where can you get a SCOBY from?
- A trusted fermentation supplier, here are a couple of examples;
- Or you can take a cutting from a friend who already brews their kombucha
The Sugar Content:
Okay so we’ve established that the sugar is the food/fuel for the SCOBY. Therefore, the sugar content impacts not only the sweetness but also the acidity of your end product. If you add to much sugar you will end up with a sweet product that continuously gets more and more acidic as time passes, not enough sugar and the fermentation may not even take place. Different recipes call for different quantities, I have found that by brewing a sweet tea with 7% of the liquids weight in sugar (70g of sugar to 1L) after 7 days of fermenting produces a nice crisp kombucha with not too much residual sweetness.
Kombucha originated in China, possibly as long as 2000 years ago, and was traditionally made with black tea ( red tea, made from camellia sineses plant) although it is made with everything from green tea, to lemon myrtle infusions, to pumpkin to ginger. Tea such as Oolong, green or white tea are ideal starting points because of their more neutral flavours, once you get confident though their is a myriad of combinations to explore. It is said that the nutrients in certain teas boost the health of your SCOBY, equally your SCOBY may struggle with some ingredients and some infusions may kill/poison your SCOBY, therefore if trying a new combination always make sure to reserve some of your SCOBY in a jar filled with 15% sugar syrup, or another batch of healthy kombucha just in case it doesn’t work out. SCOBY’s will also take on the flavour from infusions, this is why you may end up keeping multiple SCOBY’s for different flavours.
This ones pretty simple, time, temperature,light and air. Kombucha doesn’t like light, so keep it in a dark dry area, temperature ideally is anywhere from 18-29C, too cold and fermentation will proceed very slowly, too hot and it will develop off flavours. As previously stated, SCOBY requires air to thrive so don’t brew in a sealed container, cover the top of whatever jar your using with some CHUX and an elastic band or some muslin. Time, your kombucha is alive it will keep getting more and more sour and the flavour will continuously change the longer you leave it. Find a sweet point by tasting daily and then if you have too much to immediately consume freeze or pasteurise it we tend to use ours at day 7 unless we are doing a second fermentation.
Cleanliness, cleanliness, cleanliness:
Sterilize all vessels, before using, wear gloves if your transeferring the SCOBY and keep your fermentation space clean, and tidy.
My Basic Method
- 1L of water
- 4 green tea bags
- 70g caster sugar
- 1 kombucha mother and the liquid it comes with
- 50-100g of kombucha ( either some from last batch or some unpasteurised kombucha from a shop)
- Bring half the water and the sugar to the boil, whisk until the sugar has been dissolved. Add the tea bags and let them infuse for 2-3 minutes.
- Add the rest of the cold water, allow it to cool down below 35C high temperatures will kill the SCOBY.
- Once cooled introduce your SCOBY and the kombucha, and transfer to your fermentation vessel. Cover with muslin and set aside.
- Leave it to ferment for 3 days, taste, then check it every day until it has a crispness and is refreshing.
- Bottle it and refrigerate, consume within 1-2 days or freeze it.
- Additional: Chop up a handful of berries, apples, pears or any fruit that you want and put it into the bottle, pour the kombucha over the top and seal it. Leave it at room temp for 2 days and refrigerate and drink. The additional sugars in the fruit will ferment producing carbon dioxide that will give you kombucha a fizz.
- Note: always keep some of your kombucha and the SCOBY for the next batch!!!
Some good books on fermentation and kombucha:
The Noma Guide to Fermentation- Rene Redzepi and David Zilber
Wild Fermentation- Sandor Ellis Katz
Ferment For Good: Ancient Foods For The Modern Gut- Sharon Flynn
DIY Kombucha – Katherine Flynn
Looking after your SCOBY in-between batches:
I store some SCOBY in a 15% sugar solution at all times (150g sugar to 750g of water) just in case something goes wrong and I have to discard my batch thats on the go. Replace the solution every 3-4 weeks, keeping the jellyfish like SCOBY. As soon as you need to use it, cut half of it off and add it to your batch.