The fermented tea beverage made with a symbiotic culture of bacteria and yeast is kombucha.
Kombucha is usually made by fermenting sweetened black or green tea with a SCOBY, an acronym for “symbiotic culture of bacteria and yeast.” The culture often forms a rubbery, floating layer sometimes called a mother, mushroom, or tea fungus, although it is not actually a fungus or mushroom.
During fermentation, yeasts consume sugars and produce alcohol and other compounds. Acetic-acid bacteria then use some of that alcohol to create acids, including acetic acid. This gives kombucha its characteristic tart flavor and slight natural fizz. Commercial versions generally contain less than 0.5% alcohol, though levels can vary with fermentation and storage.
Kombucha is often confused with matcha, oolong, or green tea. Those are types or preparations of tea; kombucha is a fermented beverage made from sweetened tea. Despite its name in English, it is also not the same as Japanese konbu-cha, which refers to kelp tea. Claims that kombucha cures diseases are not supported by strong clinical evidence.