Traditionally, kombucha is produced by fermentation of sweetened tea by bacteria and yeast (SCOBY), a symbiotic culture of bacteria and yeast. In this study, kombucha tea beverage was prepared using 5 g of black, green, oolong and orthodox tea, 50 g of sucrose and then filtered out after 5 minutes. Then, the mixture was inoculated with 24 g of the yeast so called SCOBY (Symbiotic Cultures of Bacteria and Yeasts) and kept for fermentation for 8 days under aerobic conditions. Total acidity, pH, TSS, alcohol and total polyphenolic content was observed during the fermentation period. Sensory evaluation was also performed of all the produced kombucha beverage. The result shows that a significant drop in pH (1.53 units for black tea, 0.32 for green tea, 0.90 for oolong tea, and finally 1.92 for orthodox tea kombucha). All beverages had the highest acetic acid concentration on the 8th day of fermentation (1.2–3.6)% for black tea, (1.2–3.6) for green tea, (0.6–3.0) for oolong tea and (0.6–2.7)% for orthodox tea kombucha. kombucha made with black, green, oolong, and orthodox tea, the saccharose content decreased as fermentation progressed, reaching its lowest point on the 8th day (5.0, 5.1, 5.4, and 5.0)◦Bx. The level of alcohol rose over time, from (0.17–0.45)% for black tea, (0.12–0.40)% for green tea, (0.10–0.35)% for oolong tea, and (0.15–0.42)% for orthodox tea. The phenolic content ranging from (83.08–120.2) mg/l for black tea, (230.05–272.60) mg/l for green tea, (183.23–223.1) mg/l for oolong tea, and (117.25–150.5) mg/l for orthodox tea kombucha. From sensory points of view sensory panellist sensed a vinegar taste, while others experienced a fruity and sour aftertaste. Overall, the kombucha tea drink was considered balanced and enjoyable
Ranabhat et al. (Mon,) studied this question.