Kombucha tea is a beverage that has been consumed for centuries in various parts of the world, including Russia and China. More recently it has made its way to America, where it is both homemade and available in markets, particularly health food stores. Many claims have been made about the health-promoting qualities of the beverage; however, these claims have not been evaluated by the FDA, nor have they been backed with peer-reviewed scientific studies. The ingredients used to produce Kombucha tea consist of a probiotic culture, water, tea and sugar.
Also known as a SCOBY, for symbiotic colony of bacteria and yeast, the Kombucha culture is a pancake-like mass of probiotics living together in a cellulose matrix. Also called a mushroom, the Kombucha culture ferments over a period of weeks to months, during which time it replicates to produce a daughter mushroom. The daughter can be separated and given away, or it may remain attached to the mother Kombucha and allowed to undergo additional fermentation.
The liquid in which Kombucha ferments is a mixture of tea, water and sugar. The tea may be either green or black tea, or a mixture of the two, notes author Gunther W. Frank, who recommends 2 tsp. of green and/or black tea per quart of water. The tea should be caffeinated, as the Kombucha derives nourishment from the caffeine. This reduces the amount of caffeine present in the finished brew. As most herbal teas are decaffeinated, herbal tea is not generally used.
Water is used to brew the tea, in a mixture of 3 quarts per 5 tea bags, notes Gunther. Author Betsey Pryor advises against the use of tap water, as the chlorine present in tap water may be harmful to the culture. Purified water, including distilled water or water derived from a reverse osmosis filtration system, is often used, as is spring water.
Sugar is the primary energy source for the Kombucha culture during fermentation. White sugar, preferably organic, is recommended, although brown sugar and molasses may also be used. Due to its antimicrobial properties, honey may harm the culture and is generally not used, notes Gunther. During the two-week period of fermentaion, the Kombucha culture metabolizes the sugar to produce a variety of organic acids and carbon dioxide. These provide the carbonation and a tart flavor that many Kombucha afficionados enjoy. The Kombucha beverage contains little sugar, as the sugar is consumed by the fermentation process. The beverage contains some alcohol as a result of fermentation. Longer brew times reduce both the sugar and alcohol content.