Boil about a third of the water. Pour the boiling water over the sugar in a heat-proof bowl and stir to dissolve completely. Add the tea bags and steep for 30 minutes.

Remove the tea bags, squeezing out the liquid. Add the liquid to your large jar with the rest of the water and let cool completely.

Add the fresh kombucha and the SCOBY and stir gently. The SCOBY will eventually float to the top. Cover with a light towel and a rubber band. (The towel should not come into contact with the surface.) Put it in a cool corner of the kitchen out of direct sunlight. A cupboard is fine if you have the space.

Check after 4-5 days when it's hot, allow at least 7 days in the winter. I taste it with a clean spoon. If it doesn't taste sufficiently bubbly and vinegary, leave it another few days.

Once it tastes to your liking, remove the SCOBY with clean tongs and 1 C. of the brew, putting them in a clean, well-rinsed glass jar with a lid. Store in a cupboard until next time. This will be what you add to start the next batch. You only have to buy a bottle of kombucha the first time you make it. (Note that I no longer store mine in a plastic container.)

Refrigerate the rest. Since this is a health beverage and does contain sugar, go easy on it. It's really supposed to be used as a tonic, not drunk like soda.