Kombucha is an ancient beverage made from fermented sweet tea. Cultures are started by adding a bit of a pellicle from a previous brew to a fresh vat of cooled, sweetened green or black tea. The pellicle, also called a SCOBY for symbiotic culture of bacteria and yeast, contains both bacteria and yeast species that convert the sugars in the tea into organic acids like vinegar. The bacteria secrete a protein called cellulose that is gel-like, tough, and that forms at the surface of the culture, effectively sealing the vat of sugar off to invading microbes. Video produced by Wes Middleton.
