1. Different places of origin: Wuyi black tea is produced in Wuyishan city, Fujian Province, and Zheng Shan Xiao Seed is produced in the state-owned forests of Wuyi Mountain in the northern part of Wuyishan City, Fujian Province.
2. Tea tree varieties are different: Wuyi black tea is made from local tea tree varieties in Fujian, while Zhengshan xiaosi is made from Fujian big-leaf tea trees.
3. Different processing techniques: Wuyi Black Tea adopts the "smothering" process (i.e., fresh tea leaves are put into closed containers for fermentation), while Zhengshan Xiao Seed is a unique "smoked" process (i.e., fresh tea leaves are plucked, softened, and twisted, then smoked over pine charcoal in order to bring out the special flavor and texture of black tea).
4. The taste is different: Wuyi black tea is delicate and sweet in the mouth, the taste is softer and more refreshing; Zhenshan Xiaojiao has a strong flavor, the tea taste is very fresh, the aroma is strong, and the taste is thick.
Overall, Wuyi black tea and Zheng Shan Xiao Seed are two kinds of black tea with their own characteristics. If you like soft and refreshing black tea, then Wuyi black tea is a good choice; if you want to try a strong and thick black tea, then you can try Zhengshan Xiao Seed.