What is black tea? The "Chinese Tea Dictionary" states: "Black tea uses coarse raw materials, undergoes prolonged pile-fermentation during processing, and results in tea leaves appearing oily black or dark brown... The manufacturing steps include killing-green, rolling, pile-fermentation, and drying. It features a coarse appearance, dark brown color, and a strong, coarse aroma. Main types include Hunan black tea, Hubei old green tea, Sichuan black tea, and Yunnan-Guangxi black tea, often used as raw material for compressed tea." "Hunan Tea Technology" notes: "Black tea is mainly for border sales, with products like Heizhuan, Fuzhuan, Huazhuan, and Xiangjian. Raw black tea requires tightly rolled strips, oily sheen, orange-yellow liquor, pure aroma, mellow taste, and yellowish-brown leaves. It does not avoid smoky notes, with a pleasant pine-smoke aroma being its traditional style. The initial processing involves killing-green, initial rolling, pile-fermentation, re-rolling, and baking."

The national higher agricultural textbook "Tea Processing" defines black tea as: "Black tea is one of the six major tea categories and a unique tea type in China... Finished products include Hunan's Tianjian, Gongjian, Shengjian, Heizhuan tea, Huazhuan tea, special Fuzhuan tea, regular Fuzhuan tea, Hubei Qingzhuan tea, Guangxi Liubao tea, Sichuan South Road border tea, Yunnan compressed tea, etc... Mainly for border sales, partially domestic, and少量 overseas. Thus, it is conventionally called border tea." The book includes Yunnan-Guangxi black tea under black tea. "Yunnan tea includes Yunnan compressed tea and Guangxi Liubao tea两大类."

"The raw tea for Yunnan compressed tea comes from various tea regions across the province, mainly pressed at Xiaguan Tea Factory. A small amount is also produced in Menghai, Xishuangbanna, and Kunming. Products include compressed tea, cake tea, square tea, round tea, etc., primarily for border sales, with some domestic and overseas sales." Therefore, the authoritative textbook "Tea Processing" does not classify Pu'er tea as black tea. Yunnan Pu'er tea is made from Yunnan large-leaf sun-dried raw tea and its compressed forms, through long-term natural aging or artificial pile-fermentation. Its quality features: loose tea has thick, robust, complete strips, brown-red (called liver color) or grayish-white; various compressed Pu'er teas have neat, well-shaped, and appropriately tight forms. The liquor is rich and bright, with a unique aged aroma, brown-red leaves, and a mellow, sweet taste. Table 1 shows clear differences in processing and quality between Pu'er and black tea: ① Black tea uses coarse leaves of small-leaf tea varieties, processed through killing-green, initial rolling, pile-fermentation, re-rolling, and drying; Pu'er tea uses large-leaf sun-dried raw tea, undergoing natural fermentation or artificial pile-fermentation as a reprocessed tea. ② They differ fundamentally in appearance and internal quality. ③ Black tea is mainly compressed for border sales; Pu'er comes in various loose and compressed forms for border, domestic, and export markets.

The above material sufficiently demonstrates that Pu'er tea is not black tea.