Kombucha (often mistakenly named kombucha mushroom) is a fermentation of sweetened tea usually consisting of acid acetic bacteria and yeast species (from the genera Brettanomyces, Candida, Schzisaccharomyces, Torulaspora and Zygosaccharomyces cultures).

The kombucha culture looks a bit like a large pancake. A healthy, new culture is light in color, and will generally darken with age. Kombucha is believed to have been made by Chinese people for more than 2 millennia, but the first evidence came from Early Modern Russia, when Siberian Russian explorers brought it to Eastern Europe (today it's widely popular amongst Russians).

Paradoxically, the name kombucha comes from Japanese ("kelp tea"), and in Japan the name is applied to a totally different beverage (an infusion of brown kelp algae, which is rather salted). The Japanese call the "Western" kombucha "k�cha-kinoko" (black tea mushroom).

Kombucha is believed to be highly effective in increasing liver detoxification, due to the glucaric acid, which prevents bacterial disruption of glucuronic acid conjugates. Glucaric acid is also supposed to be an anticarcinogenic compound.

So, how do we make kombucha? We have to place the culture in a jar then filling it with cold sugar-sweetened black tea.

A new layer of the kombucha culture develops just below the surface of the tea mixture. The first "crop" is ready for consumption in 8-12 days. After removing it, more tea with sugar is added to fill the recipient.

A mature kombucha is several centimeters thick and supplies a portion of beverage every day. Once a month or two, the liquid must be filtered. When kombucha becomes too sour, the liquid must be removed, and the culture is left in clear water one night, then the recipient is filled with sugared tea again.

From time to time, slices of culture can be taken off it to start new kombucha cultures in separate recipients. Roughly 10 % of the liquid from each culture is typically kept as a "starter" liquid for the next preparation.

With another way of making kombucha, the culture is placed into a large recipient.

Water is boiled with white sugar and after removing it from the heat, black or green tea bags are immersed into the liquid. When the liquid drops to room temperature, it is added to kombucha culture. After 7-8 days, kombucha is ready.

Refrigerating kombucha for a few days before consumption allows the flavor to deepen. The starter tea sustains kombucha production only for two weeks; after that, the culture will start to dry out. After three or four layers of kombucha, the tea will become sour and will get a vinegar taste. It is important that hands and utensils that come into contact with the culture are kept extremely clean so as to prevent contamination.

If mold does grow on the surface of the kombucha pellicle, it's best to throw out the culture and start over. Unsanitary fermentation conditions may lead to adverse reactions to kombucha consumption.