Kombucha is a beverage popular for many years in the world, but little known in Poland, where is available in selected health food stores or in online sales. A drink has specific sensory qualities caused during sweet fermentation of black tea by specially prepared culture of yeast and acetic acid bacterias. Fits perfectly into the trend of functional beverages that promote well-being. Kombucha beverage has a low total sugar content (2,5 g/100 ml) and directly reducing (approx. 1 g/100 ml), with high total extract (approx. 10,5oBx), suggesting formation other organic compounds during fermentation, included in the extract. The beverage has a very low pH (3,4), and is hypertonic with high osmolality (437 mOsm/kg H2O). Therefore should not be recommended as a thirst quenching drink, but as a nutritional drink and/or regenerative, with properties resulting from the characteristics of the organic compounds formed, during the fermentation of tea.