Tea: steep 8-10 bags of plain (no oils or flavorings) organic black or green tea or about ¼ cup loose leaf tea in approximately 8 cups of filtered water. Double steep to make it decaf if you want. Let cool to room temperature.
Sugar: Dissolve 1 cup of sugar into a few cups of boiling water. Let cool to room temperature.
1 cup unflavored kombucha
Combine into a 1 gallon glass jar. Put a coffee filter on top, secured with a rubber band.
Depending on the size of your container, ferment for 7-30 days, depending on how warm your house is. Do not disturb, as a new SCOBY layer will be forming on the top. The longer the fermentation the stronger the kombucha will be and it will also have less sugar. The SCOBY may turn brown, which is fine. Anything green or black, means mold is present and you will need to throw it out.
Remove new and old SCOBY (may or may not be attached to each other) and save for future batches. Pour kombucha into smaller containers, add fruit/juice to taste, and place the cap on VERY lightly. If you put it on tight it may explode. Keep on the counter for up to 2 full days which makes it fizzy and gives it a great fruity flavor. You can then remove the fruit before putting it in the fridge. Putting it in the fridge should stop the fermentation and you can secure the lids tightly.
For more information (and videos) check out Cultures for Health