Kombucha

Ingredients

• 1 jar
• 3-5 tbsp black or green tea
• 2 cups sugar
• kombucha scoby
• 1-2 l water
• 3-5 cups water
• 4 l water
• optional additional teas
• optional juices
• optional fruits
• optional spices

Method

Kombucha is a bacterial-fermentation where acetic acid bacteria and yeast convert sweet tea into a lightly sour, carbonated drink. The process hinges on temperature-control: you need consistent warmth (20–26°C) to keep the microbial colony active without killing it, and you need to prevent contamination by creating an anaerobic barrier that still allows gas exchange.

Boil 4 litres of water. While it cools, sterilise your fermentation jar and all equipment with boiling water — this removes competing bacteria that will sour your batch prematurely or introduce off-flavours. Steep 3–5 tablespoons of black or green tea (or a combination) in 3–5 cups of that boiling water for 5–10 minutes, then strain. Add 2 cups of sugar — this is not optional; the bacteria and yeast need it to function. Dissolve it completely, then dilute with the remaining cooled water until the liquid reads below 40°C on a thermometer. This matters: a hot scoby (the cellulose mat of living culture) will die; a cold one will stall.

Add the scoby and pour everything into your jar. Cover the opening with a clean cloth, coffee filter, or paper towel secured with a rubber band. This lets carbon dioxide escape and oxygen in without admitting insects or dust. Position the jar in a warm, dark corner — a cupboard is ideal — and leave it undisturbed for 10–14 days. After a week, taste it: you're looking for a balance between residual sweetness and vinegar sharpness, with the first faint prickle of carbonation on your tongue. The exact window depends on room temperature and your preference; warmer kitchens ferment faster.

Once ready, strain four-fifths of the liquid into glass bottles with tight-sealing lids. Leave the remaining fifth in the jar with the scoby as a starter culture for your next batch. If you want flavoured kombucha, add fruit juice, sliced fruit, or spices to the bottles now — they will ferment slightly over 3–7 days, adding complexity without consuming all residual sugar. Seal the bottles and keep them at room temperature. Open each one every other day to release pressure; sealed bottles can burst. When the carbonation pleases you, refrigerate. The cold stops fermentation almost entirely and extends shelf life to several weeks.