Second ferment
Base kombucha + a bit of fruit → sealed → 1–3 days at room temp = fizz.
Do this
Fruit in the bottle first
2 tbsp fresh fruit purée or juice per 500 ml bottle. Strawberry, mango, apple, pomegranate work well.
Top with base 'buch
Leave 2 cm headroom. Cap tight.
Wait 1–3 days at room temp
Burp bottles daily (release CO₂) for the first two days.
Fridge → serve cold
Chilling stops the fermentation. Now you have fizzy fruit 'buch.
Full write-up after the first non-exploding bottle.