Tyler's recipe book
Makes About 2 litres
30g unrefined sugar
700g used coffee grounds
300ml mature kombucha (homemade or shop-bought)
1 kombucha scoby (ask a friend or buy it online)
Measure two litres of just-boiled water into a heatproof glass or ceramic jug, stir in the sugar and spent coffee grounds, and leave to infuse overnight. The next day, strain the flavoured water through a non-metallic sieve into a fermentation jar, add the kombucha and gently float the scoby on top. Cover the jar with a clean tea towel, secure it in place with a rubber band or string, then put the jar in a warm, roughly 20C spot out of direct sunlight.
After a few days, start tasting the kombucha – depending on the ambient temperature, it will take between three and 14 days to ferment. Strain into sterilised bottles, keeping back 300ml of backslop for the next batch, and store in the fridge, or leave to ferment a second time, which will carbonate the drink.