The color and taste of black tea are very different from oolong tea and green tea. The black tea leaves are black, the tea soup is dark red, the taste is not bitter, the property is warm, and the taste is relatively mellow. In terms of storage, black tea is less susceptible to changes in taste due to time, which is a greater advantage than green tea. Because of this, it spread to Europe and the United States in the early days and became one of the most popular drinks in Europe and the United States.