Black tea can help digestion, stimulate appetite, induce diuresis, eliminate edema and strengthen heart function. The American Heart Association once concluded that black tea is "one of the drinks rich in flavonoids which can eliminate free radicals and have anti-acidification effect, and can reduce the incidence of myocardial infarction". Chinese medicine believes that tea is also divided into cold and heat. Green tea, for example, tastes bitter and cold, and is suitable for drinking in summer to cool off the heat. Black tea and Pu 'er tea are warm and suitable for drinking in winter. Black tea originated from Wuyishan tea area in Fujian Province, which has more fermentation processes than green tea, and has to go through withering, rolling, fermentation, drying and other production processes, and belongs to fully fermented tea. The main producing areas are China, Sri Lanka, Indian, Indonesian and Kenyan. Besides Qimen Black Tea in China, Assam Black Tea, Darjeeling Black Tea, Ceylon Plateau Black Tea, Nierjiri Tea and Chuanhonggongfu, Taicha 18 in Yuchi Township, Nantou County, Taiwan Province Province is also a famous black tea product. Ingredient Efficacy During the processing of black tea, tea polyphenols are reduced by more than 90% due to chemical reactions such as promoting oxidation, resulting in theaflavins, thearubigins, flavonoids and other components. Tannic acid components are also reduced, slightly less irritating than green tea, while black tea soup is mostly dark red and less bitter.

Chen, a Chinese doctor, pointed out that people who feel uncomfortable after eating too many iced fruits and vegetables in winter can add brown sugar and ginger slices to black tea and drink it slowly while it is warm, which will make them feel more comfortable, but it is not recommended to drink iced black tea.