Keemun black tea, or Qihong for short, is produced in Qimen County, Anhui Province. It is the only black tea among the top ten famous teas in China. Keemun black tea is the best among black teas. "A vessel becomes famous only for tea, and the tea fragrance fills the guests." It enjoys a high reputation and is known as "the best of all flowers" and "the queen of black tea." In 2008, the production skills of Keemun black tea were selected into the second batch of China's national intangible cultural heritage protection list. Keemun black tea was created by Han tea farmers in Anhui Province during the Guangxu period, but the earliest historical records can be traced back to Lu Yu's "The Classic of Tea" in the Tang Dynasty. The natural conditions in the Qihong production area are superior, with many mountainous forests, warm and humid, deep soil, abundant rainfall, and many clouds and fogs, which are very suitable for the growth of tea trees. In addition, the main variety of local tea trees, the oak leaf variety, is rich in content and has high enzyme activity, which is very suitable for the production of Gongfu black tea. The tea raw materials of Keemun black tea are made from the local medium-leaf and medium-growing tea trees "Quercus leaf variety" (also known as Keemun variety). Qihong tea has a fine picking process, which can be roughly divided into three main processes: picking, primary processing and refining. Picking: Qihong tea is picked and processed immediately to preserve the effective ingredients of fresh leaves. The picking standards for Qihong tea are very strict. High-end tea is mainly made of one bud and one leaf, one bud and two leaves. The leaves are picked in batches for multiple times. Spring tea is picked in 6-7 batches, summer tea is picked in 6 batches, and autumn tea is picked less or not. Primary processing: including withering, rolling, fermentation, drying and other processes. The buds and leaves are changed from green to copper red, the tea body is formed into strips, the aroma is transparent, and it is baked on a slow fire until dry. Fermentation is a unique stage in the production of black tea and is the key to determining the quality of Qihong tea. The fermentation room temperature is controlled below 30 degrees. After fermentation, the leaf color turns red, forming the quality characteristics of Qihong tea with red leaves and red soup. The primary finished product is called black tea. Refining: After the black tea is made, it must be refined to distinguish the length, thickness, weight, and impurities. Qihong tea is very laborious to refine, so the refined Qihong tea is also called "Gongfu tea". The refining process is complicated. The finished Qihong tea is made by rough screening, shaking screening, sub-screening, tightening the door, lifting the screen, cutting, air selection, picking, adding fire, clearing the wind, splicing and packing. After the refined processing, the Qihong tea has a tight and small appearance like eyebrows, with slender and fine hairs, and a dark color; the tea aroma is fragrant and lasting, like fruit and orchid; the tea soup color and leaf bottom color are bright red, and the taste is fresh, mellow and rich. Even if it is mixed with milk and sugar, its fragrance is not only not reduced, but even more fragrant. Qimen black tea has rich nutritional value. On the one hand, it can provide rich riboflavin, folic acid, carotene, tocopherol and phylloquinone, which is an important source of fluoride in food; on the other hand, because the ingredients of Qimen black tea have multiple pharmacological effects, tasting Qimen black tea can not only make people enjoy the elegance of calmness, but also has health and beauty effects. In addition, Keemun black tea has the effects of refreshing and relieving fatigue, promoting fluid production and clearing away heat, diuresis, anti-inflammatory and bactericidal, detoxification, nourishing the stomach, delaying aging, and lowering blood sugar.