Fermentation in tea manufacturing is a vital process driven by microbial activity. During this phase, tea leaves undergo breakdown and decomposition. The essential role of bacteria comes into play, as they consume certain chemicals within the tea leaves and, in turn, produce different compounds. This microbial alchemy adds a unique and distinct flavour to the final tea product.
The fermentation of tea typically involves piling the tea leaves in a warm, humid environment and allowing microbial activity in the leaves over a period of time, which can range from months to years depending on the desired result. This process increases the tea’s complexity, deepens the color, and can produce earthy, woody, or even mushroom-like flavors.
The fermentation of pu-erh and other dark teas is a more gradual and variable transformation. Master tea makers carefully monitor temperature, humidity, and oxygen levels to guide the fermentation in a way that brings out the unique character of each tea. The end result of this fermentation is a tea that is significantly different from its fresh, unprocessed state. The microbial activity and chemical changes produce a depth of flavor that cannot be achieved through simple drying or oxidation alone. This is why fermented teas like pu-erh are so highly prized by tea connoisseurs around the world.