Optional: 1 tsp lemon zest, small knob of fresh ginger
Cook: Add berries, water, and sugar to a medium saucepan (optionally add lemon zest and/or ginger). Cook, uncovered, over medium heat until berries burst, mashing them a bit to form a thick liquid. Let cool to room temperature (to quicken this up, set pan in a sink full of cold water).
Mix: In a large glass bowl or pitcher, stir together blueberry mixture and kombucha.
Bottle: Transfer kombucha into fermentation bottles*, leaving about 2 inches empty at the top. Seal tightly.
Ferment: Place in a dark, room temperature area for 3 to 10 days, until it reaches the carbonation level you like. This process will go faster in warmer climates, and slower in cooler climates.
Enjoy: Strain the kombucha to remove pulp (optional), then chill in the fridge before serving. Can be stored in the fridge, tightly sealed, for several weeks.
*If this is your first time brewing, it may be helpful to use a plastic water bottle as a gauge. Fill a disposable plastic bottle with kombucha (leaving 2 inches empty at the top). When this bottle becomes rock hard, you’ll know the glass bottle are also ready. This will help you gauge how quickly kombucha brews in your climate and will prevent bottle explosions.