Quercetin

Have you ever tasted a "sour" flavor while savoring tea? What kinds of sour flavors can be found in tea? Why does tea have a "sour" taste? Which types of sourness are good, and which ones are not? Let’s explore these questions together! Wuyi Sourness Some high-quality Wuyi Rock Teas naturally develop “Wuyi Sourness” during their aging process. In the mid-19th century, Western tea scholars discovered "tannin" (catechin) in rock tea and isolated "Wuyi Acid." Later, it was confirmed that Wuyi Acid is a mixture of beneficial substances including gallic acid, oxalic acid, tannin, and quercetin. In 1847, Rolland isolated "Wuyi Acid" from Wuyi Rock Tea. In 1861, Hasewitz confirmed that Wuyi Acid is a mixture of gallic acid, oxalic acid, tannin, and quercetin. It's important to distinguish between the genuine Wuyi Sourness, which is "sour but not cloying," and the sour taste caused by processing errors, which can induce nausea. The latter might be referred to as "nauseating sourness." Therefore, one should not blindly pursue the Wuyi Sourness. As the saying goes: "Though Wuyi Sourness is good, don’t overindulge!" Therefore: Authentic Wuyi Sourness is good, while nauseating sourness is undesirable! Tieguanyin Sourness The false sourness in Tieguanyin, known locally…