Kombucha is a beverage made from fermented sweet tea that is usually consumed for its purported health properties. Kombucha uses a combination of yeast and bacterial cultures to produce an end product that is only slightly alcoholic and mildly acidic. Because most of the alcohol is further fermented into acetic acid, kombucha is considered a non-alcoholic beverage.
The flavor of kombucha will rely heavily on the type of tea from which it is made, the type of sugar added to fuel fermentation, and the unique blend of bacterial and yeast cultures.
In general, kombucha is slightly tart from the acetic acid content and tends to be slightly effervescent due to the production of carbon dioxide during yeast fermentation. There are many varieties of kombucha on the market today, with a wide variety of flavors to choose from.
How is Kombucha Made?
Kombucha can be made from any variety of tea, most often black, green, oolong, or yerba mate. The tea is sweetened with sugar to provide fuel for fermentation. Honey, which has antimicrobial properties is generally not suitable for making kombucha. A bacterial "mother," or culture starter, is added to the tea to begin fermentation. The brew is left to ferment for one to two weeks, during which time the culture grows and ferments within the liquid. The liquid is then tapped and consumed.
The yeast in the culture ferments the sugar into alcohol, which is then further fermented by the bacteria into acetic acid.
The alcohol level in kombucha generally stays below 0.5%, which is considered nonalcoholic by U.S. beverage standards. The acetic acid production usually keeps the acidity of the beverage around a pH of 3.0. The alcohol and pH of kombucha are usually enough to prevent contamination from undesired bacteria, mold, and fungus.
If the batch does become contaminated, the tea, as well as the culture starter, must be discarded.
The bacteria and yeast culture form a slime-like clump of cellulose within the beverage, which can then be transferred to the new batch of kombucha to continue the fermentation process. These bacterial cellulose clumps can be seen inside bottles of commercially sold kombucha. Although edible, the slime clump is usually avoided simply because of the undesirable texture.
Many claims regarding kombucha's effect on mental and physical health have been made, although none have been proven scientifically. Many claims surround kombucha's effect on digestive health because of the bacterial and enzyme content. Every batch of kombucha will have a slightly different content, although most contain a variety of acids, enzymes, and B vitamins.