Black tea is a kind of fermented tea, contains more caffeine than green tea, refreshing diuretic effect is also better than green tea. It is generally believed that black tea is "hot", especially for people with weak stomachs. Especially the small-leaf black tea, sweet flavor, no irritation. If you choose large-leafed black tea, tea flavor is stronger, you can add milk and brown sugar in the tea soup, have a warm stomach and increase the role of energy.