Add 8 black tea bags (or equivalent loose tea in a muslin bag) to the hot sugar water. Steep for 10–15 minutes to extract a robust tea. Remove tea bags or strain out loose tea and allow the sweet tea to cool to room temperature (ideally 20–27°C / 68–80°F). Cooling may take 2–4 hours; do not proceed while the tea is still hot, as heat can damage the SCOBY.

Once the sweet tea is at room temperature, transfer it to a clean 3–4 liter glass fermentation vessel. Pour in 2 cups of unflavored, unpasteurized starter kombucha (from a previous batch or a trusted source). Gently slide the SCOBY on top of the liquid.

Cover the vessel with a breathable cloth or paper towel secured with a rubber band. Place the jar in a warm, dark place with good air circulation and a stable temperature of about 24–27°C (75–80°F) if possible. Let it ferment for 7–12 days, checking flavor beginning on day 7. Taste daily: the kombucha should be slightly sweet and tangy. Longer fermentation produces a more vinegary, less sweet kombucha.

Seasonal Flavoring (example: ginger-citrus)

Prepare flavoring while primary fermentation is finishing: thinly slice 3 tbs fresh ginger and zest or thinly slice 1 tbs orange. Measure 2 tbs fresh lemon juice. Combine ginger, orange zest/slices, and lemon juice in a small bowl. If you want more carbonation, dissolve the optional 2 tsp sugar into the lemon juice (this feeds yeast during secondary fermentation).

When primary fermentation has reached the desired acidity (usually 7–12 days), remove the SCOBY and 2 cups of kombucha to reserve as starter for your next batch (store in a clean jar with some liquid).

Pour the remaining kombucha through a fine mesh strainer into a clean measuring container. Distribute kombucha evenly into sterilized flip-top bottles, leaving about 2–3 cm headspace in each bottle (approximately 500 ml per bottle if using 6 bottles from this batch volume). Add a portion of the ginger and orange to each bottle (roughly 1/2 tbs ginger + a small piece of orange per bottle) and a splash of the lemon juice mixture (about 1 tsp per bottle). If using the optional extra sugar, add ~1/3 tsp per bottle.

Bottling / Secondary Fermentation

Seal the flip-top bottles tightly and let them sit at room temperature (20–24°C / 68–75°F) for 2–4 days to carbonate. Check the bottles daily and open briefly to release excess pressure if they become very firm. Note: shorter time = lighter carbonation; longer time = stronger carbonation. Be cautious to avoid over-pressurization.

After desired carbonation, refrigerate bottles to slow fermentation. Chill at least 12 hours before serving. Keep refrigerated and consume within 2–4 weeks for best flavor, though refrigeration will slow further carbonation and acidification.

To serve: pour over ice if desired (about 1/2 cup ice per serving). Garnish each serving with an orange wheel or piece of candied ginger. Pour carefully to avoid stirring up sediment from the bottle; tilt the bottle and glass to minimize fizz overflow.