Why is it necessary to separate tea leaves from the brew when making black tea?

YuanJia131

For most teas, brewing requires "tea-water separation," with only variations in water temperature and time. However, for fully fermented black tea, due to the internal quality changes resulting from the fermentation process, "tea-water separation" is an absolute necessity.
Simply put, brewing tea is essentially a process of distribution and balance between the internal components of tea leaves and water, with tea quantity, water temperature, and time being the key factors.

During the brewing of black tea, various substances such as aromatic compounds, amino acids, theaflavins, thearubigins, water-soluble polysaccharides, tea polyphenols, and caffeine dissolve into the tea liquor at different times and to varying degrees. As the brewing time extends, the aromatic compounds in the tea liquor undergo transformation and volatilization, while theaflavins and thearubigins convert into theabrownins. The concentration of bitter and astringent tea polyphenols and caffeine becomes higher than that of the fresh, mellow, and sweet amino acids and polysaccharides. Consequently, the tea liquor loses its aroma, darkens in color, and develops a pronounced bitterness.
So how should you separate the tea leaves and brew a pot of tea with perfect color, aroma, and taste? The key lies in controlling the three elements: tea quantity, water temperature, and steeping time.
The standard tea-to-water ratio is approximately 1:50, with the water temperature typically maintained at around 95°C. The first infusion should be extracted quickly, measured in seconds, while subsequent infusions can be extended accordingly. Specific adjustments can be made based on personal taste preferences and tea quality.