In a medium pot bring 4 cups of filtered water to a boil and then turn off.
Add tea to the cotton tea bag and add to the pot to steep for 5-7 minutes. Remove the tea bag and discard the tea leaves. Rinse and air dry the cotton bag for next time.
Pour the sugar into the pot and stir. Once the sugar has dissolved, pour your sweet tea mixture into the glass brewing jar.
Fill the brewing jar with 8 cups of cold filtered water. Your jar should now be about 3/4 of the way full. Add your temperature gauge sticker to the side of the jarred check to make sure your sweet tea mixture is now somewhere between 68 and 86 degrees before moving on to the next step. If it's still too warm add another 1/2 cup of cold water.
Take your SCOBY which, if new, should be in a starter liquid pouch and add it to the brewing jar. Give it a quick stir to combine.
Cover the jar with a cotton cloth and seal with a rubber band.
Place your brewing jar in a warm place out of direct sunlight, with plenty of airflow (no closed cupboards). Leave it there for 7-9 days. By days 7-9 you should see a new cream-colored layer has grown on the top of your brew. This is your new SCOBY! Try not to disturb your new culture as you taste test your brew with a spoon. If you like the taste, then you're done! If it's still a little too sweet then put the cloth back on and let it ferment for a few more days.
You can enjoy your kombucha plain, or if you really want to blow your taste buds out the water then continue with this second stage of the fermentation process.