Fermentation affects the smell of the tea and typically mellows its taste, reducing astringency and bitterness while improving mouthfeel and aftertaste. The microbes may also produce metabolites with health benefits. The fermentation is carried out primarily by molds.

Is fermented tea leaves good for you?

Kombucha is a fermented tea that has been consumed for thousands of years. Not only does it have the same health benefits as tea — it's also rich in beneficial probiotics. Kombucha also contains antioxidants, can kill harmful bacteria and may help fight several diseases.

Are all tea leaves fermented?

While fermentation is also referred to in the production of brewed teas, this is inaccurate. Some herbal teas on the market today include probiotic cultures alongside tea leaves to maintain gut health but the tea itself hasn't been fermented. Most dried teas however don't use live cultures at all during production.