1, overnight black tea leaves water is not recommended to drink. In accordance with the drinking habits of black tea are basically now drink, rarely drink a cold tea, not to mention the overnight black tea. Not drinking black tea exposed to the air, the tea will gradually oxidize, the taste of tea will not only deteriorate but also cause discomfort.

2, after the brewing of black tea, did not finish drinking, in the hot summer, high temperature environment, the tea is more prone to deterioration, and even sour, and there may be small insects crawling through, roughly the tea can not drink.

3, black tea placed for a long time, the tea soup becomes cold can not drink, especially cold and weak people, drinking is likely to lead to diarrhea. Overnight black tea can not drink but can be used to water flowers, is a kind of celestial fertilizer, promote the growth of flowers.