The fermentation process brings good yeasts and bacteria into the sweet tea, and that’s what differentiateskombucha from just plain old sweet tea. We eat and drink a lot of really great fermented food: wine, beer, bread, chocolate, cheese and pickles are just a few examples.
And kombucha is another one to add to the list.
All you need to make kombucha is tea, sugar, water and some kombucha culture (a SCOBY + starter tea).
Similar to how sourdough bread bakers require a little bit of a “mother” or “starter” dough from a previously fermented batch of sourdough to create a new loaf, kombucha requires some kombucha “starter” to create more of itself. It requires a bit of itself to replicate itself. This is why it’s important to get a quality culture (a SCOBY) with a good amount of “starter tea” which is basically just another word for plain kombucha that’s successfully gone through the fermentation process. You can use that “finished” kombucha to inoculate a new batch of tea with bacteria and yeast to turn the sweet tea into kombucha.
At the end of the first fermentation process, you end up with fully drinkable (albeit unflavored) kombucha. You can undergo a second fermentation process to bottle-condition your kombucha in a sealed container (like champagne or beer) if you want your kombucha to be bubbly.