In fact, it is a special symbiosis of Bacteria and yeast which is similar to the fungus (flat, smooth and slimy).The mass is placed on the tea surface as a thin layer. In consecutive fermentation processes, a newer layer is added. The sweet tea is fermented for 7-14 days and the result is Kombucha.
In his book, ”Kombucha, an ancient salutary and therapeutic tea”,Dr. Helmut Golz has mentioned many active bacterias and yeasts in the process. These yeasts have the role of balancing the body metabolism, blood cleaning, strengthening immunity system and the kidney poison excretion.
The other useful organic materials result from Kombucha fermentation are: Glucuronic acid, Gluconic acid, Acetic acid, Carbonic acid, Lactic acid, Oxalic acid, Malic acid, Butyric acid, Propionic acid, Ascorbic acid, Succinic acid, Nucleic acid, Itaconic acid, Antibiotic, Fructose, Citric acid (Vitamin C), Vitamin D, group B vitamins: B1 (Thiamin), B2 (Riboflavin), B3 (pyridoxine), B6, B12 (Cobalamin), B9 (Folic acid), and some enzymes such as: Invertase, Amylase, Catalase, Saccharase (1).
As mentioned before, Kombucha is a polysaccharide layer of yeasts and bacteria. At first, the yeasts of the medium break down Sucrose which result to Glucose and Fructose. Fructose is converted to Glucose by isomerisation which are then consumed by yeasts and they in turn produce organic acids such as Glucuronic acid, Lactic acid, Acetic acid, Gluconic acid, etc.
(1) .Sieverset al.; Microbiology and fermentation of balance in a kombucha beverage obtained from tea fungus fermentation, Systematic and Applied Microbiology 18 , 1996, 590-594
.Mayseret al.; The yeast of spectrum of tea fungus Kombucha. Mycoses, 34, 1995, 289-295
.Toeh, A. L., Heard, G. & Cox, J.; Yeast ecology of kombucha fermentation, J. Food Micribiology, 95, 2004, 119 -126
.Steinkraus, K. H.; Indigenous Fermented Food, Tea Fungus/kombucha, Marcel Dekker Inc. New York, 1996, 493-496