For the Base:

1. Place 6 cups of water in a large 4-quart pot. Transfer to the stovetop and bring to a boil. Remove the pot immediately from the heat.
2. Add the sugar, whisking until dissolved.
3. Submerge the tea bags in the hot water. Steep for 25 minutes.
4. Remove and dispose of the tea bags. Pour in the remaining 6 cups of water and whisk to combine.
5. Let cool to room temperature, no higher than 75°F, whisking occasionally.
6. Whisk in the starter liquid.

For the First Ferment:

1. Carefully pour the base liquid into a clean 1-gallon glass jar. Gently add the SCOBY to the liquid.
2. Wipe away any excess liquid droplets around the rim and outside of the glass jar with a clean towel or paper towel.
3. Cover the top of the jar with a clean, lint-free, tight-weave cloth such as a kitchen towel, bandana, or t-shirt. Tightly secure the cloth around the rim with one or two rubber bands.
4. Carefully transfer the jar to a flat and stable surface in a location of the house that is between 65 and 75°F with good airflow, away from any direct sunlight. Do not place it in a tight, dusty, enclosed location without adequate airflow like a cabinet.
5. Allow the jar to sit undisturbed for 1 week before testing. A new SCOBY will start developing on top of the liquid.
6. Remove the towel from the top and insert a clean straw or ladle to remove and taste some of the liquid. The liquid should have an approachable, but not overpowering, sour or vinegar-y taste to it, and it should be subtly sweet.
7. If you prefer a more sour taste, resecure the opening of the jar with the towel and rubber bands and allow it to sit for 5 more days before retesting.
8. Continue retesting in 5-day increments to achieve your preferred level of acidity. This could take 1-3 weeks total.

For the Second Ferment:

1. When the liquid has reached your preferred level of sourness, remove the towel. Remove the SCOBY that formed on top of the liquid, and store it to make another batch of kombucha.
2. Set out 6 16-ounce Grolsch bottles assembled with airtight swing-top caps.
3. Using a funnel, pour 1/8 to 1/4 cup of fruit puree, fruit juice, fruit syrup, or simple syrup in each of the bottles.
4. Using a funnel, pour the kombucha into each bottle, leaving about 3/4-inch headspace at the top.
5. Wipe off any excess liquid at the lip of the bottles with a clean towel and seal each bottle with the swing cap. Do not shake.
6. Store the bottles in the same location where you completed the first fermentation, or preferably in a closed cabinet in case of potential carbonation explosions. Good airflow is not necessary for this step.
7. Allow the liquid to ferment undisturbed for 1-3 days.
8. Transfer to the refrigerator to halt fermentation. Chill for at least 24 hours before opening and drinking.
9. Sealed bottles may be stored in the refrigerator for up to 30 days. Store open bottles in the refrigerator for up to 3 days.