There's a rich variety of teas, broadly categorized as green tea, white tea, dark tea, black tea, yellow tea, and scented tea. This classification stems from the commonly used global categorization, dividing tea into unfermented, semi-fermented, and fully fermented types.
Green tea, unfermented and bursting with the natural essence of fresh leaves, maintains a vibrant green flavor. On the other end, black tea, fully fermented, undergoes significant changes in leaf composition, resulting in its distinct features—red soup, red leaves, and a fragrant, sweet aroma. Then there's Oolong tea, a semi-fermented variety that blends the best of both black and green teas, offering a delightful aroma and refreshing taste.
White tea falls into the slightly fermented category. Unlike other teas, it isn't cured or rolled but undergoes a simple sun-drying or slow-fire process. Dark tea, oily black or dark brown due to extensive fermentation, belongs to the post-fermented category. Lastly, yellow tea, lightly fermented, develops its unique characteristics through a controlled heating process, resulting in its distinctive Huangyehuangtang profile.
Now, what exactly is tea fermentation?
Except for dark tea, the fermentation of tea doesn't rely on external microorganisms; instead, it's driven by the tea's enzyme catalysis.
When freshly picked tea leaves are tender and delicate, any rough handling during production can damage their cells, creating wounds. These wounds, when exposed to enzymes and oxygen, undergo a noticeable transformation—turning red and discoloring. This transformative process is what we refer to as fermentation.