The transformation of sucrose into glucose, fructose, gluconic acid, ethanol, and acetic acid was determined during a 60 day tea fungus fermentation. Black tea containing 67.5 g sucrose per litre was inoculated with 10% fermentation broth including the cellulose containing coherent top layer of a previous tea
fungus fermentation. The microflora embedded in the cellulose/acetan layer was characterized as a mixed
culture of Acetobacter xylimtm and Zygosaccharomyces sp., respectively. The yeast cells converted suo
crose inro glucose and fructose. Fructose was metabolized prior to glucose. The pH value of the kombucha
beverage decreased during fermentation from 3.75 to 2.42 as a result of acetic acid and gluconic acid
formation. A fermentation balance of the substrates sucrose, glucose, fructose and products ethanol, acetic
and gluconic acid and CO2 was calculated based on the carbon·mass (g substrate x number of C·atoms x
121 molecular weight of suhstrate) as parameter. The total carbon-mass at the start of the fermentation
was 30.5 g. The analogous values obtained after 10,20,30 and 40 days were 30.7 g, 30.5 g, 28.6 g, and
30.5, respectively. The good stoichiometry implies that all major fermentation products have been accounted for.