Bring half of the water (7 cups) to a boil in a Dutch oven or large pot. Remove from the heat and stir in the sugar to dissolve. Drop in the tea bags or loose leaf tea and steep until the water is completely cooled. This will take a few hours.

Stir in the remaining water. Remove and discard the tea bags. (If using loose leaf tea, strain out the tea leaves.) Stir in the pre-made kombucha.

Pour the mixture into a clean 1-gallon or larger glass jar. With clean hands, gently place the scoby on top. Cover the mouth of the jar with a clean cotton dish towel, a few layers of cheesecloth, or paper towels secured with a rubber band.

Store at room temperature, out of direct sunlight and where the jar won’t get jostled. Ferment for 7 to 10 days, checking the kombucha and the scoby periodically. It’s not unusual for the scoby to float at the top, bottom, or even sideways during fermentation. A new cream-colored layer of scoby should start forming on the surface of the kombucha within a few days. It usually attaches to the old scoby, but it’s ok if they separate. You may also see brown stringy bits floating beneath the scoby, sediment collecting at the bottom, and bubbles collecting around the scoby. This is all normal and signs of healthy fermentation.

After 7 days, begin tasting the kombucha daily by pouring a little out of the jar and into a cup. When it reaches a balance of sweetness and tartness that is pleasant to you, the kombucha is ready to bottle.

With clean hands, gently lift the scoby out of the kombucha and set it on a clean plate. If you’re planning to make another batch of kombucha right away, measure out your starter tea from this batch of kombucha and set it aside for the next batch.

Divide the mango between bottles, then pour the fermented kombucha into the bottles using a small funnel. Leave about an inch of head room in each bottle. Seal the bottles. Store the bottled kombucha at room-temperature out of direct sunlight and allow 1 to 3 days for the kombucha to carbonate. If you bottled in plastic bottles, the kombucha is carbonated when the bottles are rock-solid; if you bottled in glass, intermittently open one of the bottles to check the carbonation (it will re-carbonate quickly once you put the cap back on).

Once carbonated, refrigerate the kombucha for at least 4 hours to chill it down. The kombucha will keep in the refrigerator for several weeks. If desired, strain the kombucha as you serve it to remove the mango.