Steep two bags of black tea. You could use one filled tea infuser instead if desired.
Step 3: Add sugar
Add about one fourth cup of sugar to the steeped tea. Depending on the size of your jar, you may want to add more. The sugar feeds the fungus that ferments the tea. You can always add more sugar if needed.
Step 4: Let it cool
Make sure that you let the tea cool.
Step 5: Begin a SCOBY
The SCOBY (symbiotic culture of bacteria and yeasts) is what ferments the tea. If you do not have a SCOBY to start fermenting your tea, you can begin making it by simply pouring in a bottle of unpasteurized kombucha. Your first SCOBY will grow in about two-three weeks and will be about 1/4 inch thick.
Step 6: Dealing with the SCOBY
After growing your first SCOBY or if you acquire one, you will discover that a new SCOBY will grow on top of your first. After your tea has fermented, split the old SCOBY and the new SCOBY apart. Make sure your hands are very clean and try to do your best not to touch the SCOBY too much.
Step 7: Pour out fermented kombucha
Now that the SCOBYs are out of the jar, pour the fermented tea into a clean jar. Make sure you pour slowly as the tea is very fizzy. You can store the tea to drink in the fridge. Also, make sure that you pour it into a glass as plastic reacts with the tea and is not good for you.
Step 8: Setting up the new batch
Pour your cooled black tea/sugar mixture into the kombucha jar to start your next batch. Leave about a half inch of room at the top for the SCOBY and the second SCOBY that will grow on top.
Step 9: Put in your SCOBY
Put your first SCOBY in with the tea and give your other SCOBY to a friend to start their own kombucha. Some people take their second SCOBY and dry it. It dries into a leathery material.