Let’s make Kombucha Tea, time and a little attention
Start with a practical sweet-tea ratio, a healthy SCOBY and enough mature starter liquid, then follow the batch by temperature, aroma and taste—not the calendar alone.
The first-batch calculator
This conservative recipe uses 20% mature starter kombucha. It is designed for a fresh, proven culture and plain black tea or a black-and-green blend.
Choose 500–10,000 ml. Use a jar with enough headspace above the liquid.
Your brew card
2 L batchTemperature20–23°C
Begin tastingFrom day 7
Add the clean SCOBY mat supplied with your culture, but do not count it as a substitute for the measured starter liquid.
A conservative first ferment
Use clean equipment. Steep plain tea for about 10 minutes, remove the leaves or bags, then dissolve the sugar while the tea is hot.
Keep the tea covered and cool it promptly to 20–23°C. Hot tea can damage the culture; slow cooling also leaves sweet tea exposed for too long.
Pour in the measured, tart, unflavoured starter liquid, then lower in the clean SCOBY mat. Cover with tight-weave cloth secured against fruit flies.
Ferment out of direct sun at 20–23°C. A new pale SCOBY layer may form while the older one floats, sinks or sits sideways; any of those positions can be normal. Begin tasting around day 7.
When the tea smells gently vinegary and tastes less sweet and pleasantly tart, reserve 20% as starter for the next batch, keep the SCOBY mat with it, and refrigerate or bottle the rest.
Meet the SCOBY
SCOBY stands for “symbiotic culture of bacteria and yeast”. It is the living community that turns sweet tea into kombucha, producing gentle fizz, tartness and the pale layer at the surface.
Most brewers call that rubbery cellulose mat the SCOBY, but the tart starter liquid carries the same culture and gets a new batch going quickly. Use both when you have them, and never replace the measured starter liquid with a larger mat.
Before you brew
A plain 2.5–3 L jar for a 2 L batch, with space left above the tea.
Tight-weave cloth or a coffee filter, secured so fruit flies cannot enter.
Temperature changes fermentation speed; an uncontrolled warm spot is not a shortcut.
Measure the starter liquid rather than judging it by the size of the SCOBY mat.
Before you drink it
Treat homemade kombucha as containing alcohol, caffeine and residual sugar. The amounts cannot be known from taste, time or fizz alone.
Discard the entire batch and SCOBY if you see dry fuzzy mould, pests, or smell anything rotten or putrid. Do not scrape, rescue or reuse it.
Unpasteurised kombucha is not recommended during pregnancy. Immunocompromised people and anyone requiring strict alcohol avoidance should seek suitable professional guidance or choose a tested product.