Whether to wash tea depends on the specific tea varieties.

Green tea, white tea in the Pekoe Silver Needle and other raw materials tender tea, generally not recommended to wash tea. Because the process of making these teas is relatively delicate, the first brew can show the aroma and taste of the tea well, and washing tea may lose its essence.
Oolong tea, black tea, Pu’er tea, etc., washing tea is a common practice. Oolong tea production process may be mixed with dust, washing tea can remove impurities, but also let the tea stretch, better stimulate the aroma; black tea and Pu’er tea are post-fermented tea. After a long period of storage, washing the tea can wash away the dust that may be contaminated during storage, and it can also awaken the activity of the tea, so that the subsequent brewing tastes better.