Introduction:
Kombucha is a fermented tea beverage produced by using a symbiotic culture of bacteria and yeast, so-called SCOBY. The tea fungus comes from the regions f East Asia, and was brought to Europe from eastern Siberia. Kombucha is also known under other names, modst commonly as Chinese or Japanese mushroom. In process of fermentation of kombucha many metabolites are produced which are responsible for its pro-health properties.

Objective:
The aim of the study is to present a review of the current state of knowledge concerning the chemical reactions, and chemical and microbiological composition of kombucha.

Brief description of the state of knowledge:
The components found in the beverage are organic acids, mainly acetic acid, vitamins and mineral components, polyphenols, flavonoids, enzymes and fats, as well as sugars. In microbiological terms, it is a mixture of acetic acid and lactic acid bacteria and yeast. Acetobacter xylinum bacteria and Schizosaccharomyces pombe yeast are most often present in the beverage. Yeast cells consume most of the fructose in the process of glycolysis, producing ethanol and carbon dioxide. In turn, ethanol is converted into acetic acid due to acetic acid bacteria present in the beverage. Kombucha shows antimicrobial, antioxidant, anti-diabetic properties, reducing the level of cholesterol, supporting the immune system, and also stimulating liver detoxification.

Conclusions:
Differences in chemical and microbiological composition of kombucha depend mainly on the variety and type of tea, the amount of sugar used, temperature, pH, and fermentation time.