Kombucha Tea Fermentation: A Review

Kombucha tea is made by aerobically fermenting a sweetened tea infusion with a kombucha culture, a symbiotic culture of bacteria and yeasts. The resulting beverage is usually non-alcoholic, sour and refreshing, but not naturally sparkling. Many consumers are drinking kombucha because of its alleged health effects and as kombucha tea is increasing in popularity, consumers are increasingly demanding kombucha beverages of better quality. To better adapt their products to these consumer demands, brewers are looking to the scientific knowledge about kombucha for answers. However, the scientific exploration of this complex naturally fermented beverage is still limited. This review paper presents the current state-of-the-art. To further deepen the understanding of the kombucha fermentation process and to help brewers in their search for higher-quality beverages, the microbial species diversity and its dynamics during the fermentation process should be investigated in detail, as well as the kinetics of the substrate consumption and metabolite production, and the relationship between the substrate and metabolite concentrations, and the consumer preferences for the resulting beverage.