Homemade kombucha is a lightly sour, fizzy, probiotic drink made by fermenting sweetened tea with a jelly-like culture called a SCOBY (Symbiotic Culture Of Bacteria and Yeast).
The basic process is simple: brew and sweeten black or green tea, let it cool, add the SCOBY along with a bit of already-fermented kombucha, cover the jar with cloth, and let it sit at room temperature for 7-14 days.
How do you feed a SCOBY and keep it alive?
A SCOBY consumes the sugar in the tea as food with every batch it ferments, so preparing fresh sweetened tea for each new round keeps the culture alive and active.
When it's not in use, a SCOBY can be kept at room temperature in a "hotel" jar made of its own kombucha liquid; that liquid both feeds it and forms an acidic environment that protects against harmful microorganisms.
What determines the fermentation time?
A seven-day ferment produces a sweeter, mildly tart result, while getting closer to fourteen days brings out a sharper, more vinegary flavor — the timing mostly comes down to personal taste.
Room temperature during fermentation also matters: 24-27°C is ideal, and fermentation slows down noticeably in cooler spaces.
What's a second fermentation, and why do it?
After the first ferment, the liquid can be strained, mixed with fruit or spices, and left to sit a few more days in sealed bottles — this step is called second fermentation and gives the drink its natural fizz.
The bottles need to be sealed tightly for this, but since too much carbonation can cause a bottle to burst, open them briefly once a day to release pressure.
What if mold shows up on the SCOBY?
If a dry, fuzzy patch — usually green, blue or black — forms on the SCOBY's surface, neither the culture nor the liquid underneath it is safe to drink, and it should be discarded outright.
This usually comes from dirty equipment or a weak acidic environment; you'll need to start over with a new SCOBY or one grown from store-bought kombucha.
Who should be cautious about drinking kombucha?
Because kombucha can contain a small amount of alcohol and affects gut flora, pregnant or breastfeeding people, those with a weakened immune system, and young children should check with a doctor before drinking it.
Since homemade kombucha's fermentation time and acidity are more variable than store-bought versions, it's a good idea to start with small amounts the first few times.
In short
Homemade kombucha comes from fermenting sweetened tea with a SCOBY for 7-14 days; the time and temperature determine how sharp the flavor turns out.
Feed the SCOBY fresh sweetened tea regularly, and discard the culture without tasting it if you spot any sign of mold.
Attention Reader
This content is for information only and is not a substitute for medical advice. Consult your doctor before making any decision about your health.