Step 1: Bring 4 cups of filtered water to a boil in a large pot. Remove from heat, add tea bags/loose leaf tea, and stir in the sugar until fully dissolved. Let steep for 5-7 minutes (black tea) or 3-5 minutes (green tea), then remove tea bags/sachet.
Step 2: Add the remaining 8 cups of cold filtered water to the hot sweet tea. This helps cool it down quickly. Ensure the tea is completely cooled to room temperature (68-80°F / 20-27°C) before proceeding.
Step 3: Pour the cooled sweet tea into a clean 1-gallon glass jar. Add the 2 cups of starter kombucha. Gently place your SCOBY into the jar. It’s okay if it floats, sinks, or hovers.
Step 4: Cover the mouth of the jar with cheesecloth or a coffee filter and secure it tightly with a rubber band. Place the jar in a warm spot (70-75°F / 21-24°C) away from direct sunlight for 7-14 days.
Step 5: Begin tasting your kombucha with a clean spoon after day 5. When it reaches your desired balance of sweet and tart, it’s ready for secondary fermentation. Reserve 2 cups of the finished kombucha along with your SCOBY for your next batch.
Step 6: Pour the remaining kombucha into airtight glass bottles, leaving about 1-2 inches of headspace. Add your desired flavorings (e.g., fruit puree, juice, grated ginger, herbs). Seal bottles tightly.
Step 7: Let the flavored kombucha sit at room temperature for 2-4 days for secondary fermentation and carbonation. ‘Burp’ bottles daily if they become too carbonated by gently opening and re-sealing.
Step 8: Once carbonated to your liking, transfer the bottles to the refrigerator to slow down fermentation. Serve chilled and enjoy your homemade kombucha!