In a pot, bring the water to a boil. Remove it from the heat and stir in the sugar until fully dissolved. Add the tea bags or tea leaves and let the tea steep until strong.
Once the tea has steeped, remove the tea bags or strain out the tea leaves. Let the sweet tea cool completely to room temperature. This part matters because adding a scoby to hot tea can damage the culture.
Pour the cooled sweetened tea into a clean glass jar. Add the starter tea, then gently place the kombucha scoby into the jar.
The starter helps lower the pH and gives the batch a good beginning for fermentation. If the scoby floats, sinks, or sits sideways, that is all normal.
Place a coffee filter or clean cloth over the top of the jar and secure it with a rubber band. This keeps dust and insects out while still allowing airflow.
Set the jar in a warm room temperature area out of direct sunlight. Place it in a room temp spot that stays around 70 to 78 degrees. Temperature makes a big difference in how quickly kombucha will ferment. Let the first fermentation continue for 7 to 14 days. I start tasting around day 7. If I want a sweeter brew, I stop earlier. If I want a more tangy homemade kombucha, I let it go longer.
Once the first ferment tastes the way I like it, I remove the scoby and set aside 1 cup of kombucha as starter tea for the next batch.
At this point, you can drink the kombucha as-is, or you can pour it into bottles for a second fermentation. If I am doing a second ferment, I like to add a small amount of fruit juice or sugar to each bottle before filling it with kombucha.
Seal the bottles and let them sit at room temperature for 1 to 3 days. This second fermentation helps build carbonation and deepen the flavor.
