A kombucha culture is a mat of symbiotic microorganisms used in the production of kombucha, a fermented tea prepared in Russia and other parts of Asia. This tea is produced commercially in some regions, but people can also make their own kombucha. Cultures are available through mail order companies and from people who are preparing their own kombucha at home. Some people believe that kombucha has health benefits, while others simply enjoy the flavor.
The culture consists of bacteria and yeasts which have a symbiotic relationship with each other. When the culture is added to sweetened tea, the culture feeds off the sugar and the tea, fermenting the tea in the process. The tea develops a tangy and complex flavor. Once the tea is flavored to taste, the culture can be removed to start a new batch of kombucha. Kombucha cultures can be forced into dormancy by being stored in the refrigerator, allowing people to control the amount of kombucha they produce.
With each batch, the culture grows larger. It starts out as a thin sheet which gradually develops into a leathery mat. Eventually, a kombucha culture can be separated into two pieces by pulling the layers apart, allowing people to pass the second culture on to someone else or to keep it dormant in the event that the original culture becomes contaminated and they need to start over again.
The kombucha culture includes a mix of organisms which tend to resist growth by other organisms, in part by lowering the pH of the brew. Contamination does happen, however; for example, the kombucha culture can become moldy. In these situations, the culture needs to be discarded. People can reduce the risk of contamination by handling cultures with clean hands, using teas at room temperature for fermentation, and covering the kombucha with a cloth while it ferments to allow the culture to breathe while also keeping flies and fungal spores out.
Kombucha cultures, also known as mothers, mushrooms, or symbiotic colonies of bacteria and yeast (SCOBYs), are quite hardy. When they are handled properly, they can be used for extended periods of time and also develop unique characteristics which can contribute to the overall flavor of the kombucha. Some yield more fruity drinks with a soft finish, while others produce more sharp, acidic drinks. People who make their own kombucha and pass on cultures can provide handling tips so that new batches will taste like those made with the original kombucha culture.