Kombucha is a fermented tea beverage, made by adding a symbiotic culture of bacteria and yeast (SCOBY) to a solution of tea and sugar. During the course of the week-long (or more) fermentation process, the cultures metabolize the sugar and tea components to render a naturally carbonated beverage, with a slightly sweet-tart flavor, full of healthy components like B vitamins, organic acids, antioxidants, and trace amounts of alcohol.