A light, fizzy drink similar to soda.
Bring the water to a boil. Once boiling, remove from heat and stir in sugar until dissolved. Add the tea bags (having removed any metal staples first) and let it sit until cooled to room temperature.
In a sterile, glass jar or bowl pour 1/2 a cup of kombucha from previous batch and pour in cooled tea. With clean hands, place the scoby in the tea.
Cover the container with a cloth or coffee filter (something to allow air in but not bugs) secured by tape or a rubber band.
Set the container in a dark, room temperature place with a bit of ventilation. [A closet works if it is warm and gets opened several times a week.]
Let it sit for 14 days. At this point you can taste test for preference. If it is still too sweet, let it sit a few more days to eat up the rest of the sugar.
Remove the kombucha from the closet. By this time there should be another freshly grown scoby (kombucha baby) on top of the old scoby (mother).
Take off the covering and with clean hands remove the scobys and separate them if they are grown together. Store the scobys submerged in kombucha in a glass, airtight container in the fridge. Make sure the scobys are not in contact or near metal! If your container has a metal lid place a plastic wrap barrier over the top before putting the lid on. Metal kills a scoby even if it's not in direct contact.
If you want, you can strain the kombucha through cheese cloth to filter out the fine strings of "mother" left behind. I don't usually bother with this process because they all fall to the bottom and don't come out when you pour a glass. Near the end, I fish the strings out with a fork.
At this point you can store the kombucha in the fridge and enjoy!
Or you can do a second ferment with berries.
After removing the scobys from the kombucha, throw in a handful of fresh or frozen berries of your choice (about a cup). Put a tight lid on and let it sit on your counter for 3 days.
Three days later remove the berries. Place your flavored kombucha in the fridge and enjoy!