As a traditional beverage in the capital, Jiulongzhai Sour Plum Soup can trace its origins back to the Qianlong period of the Qing Dynasty. According to legend, a small businessman came to the capital to join his uncle who worked in the imperial tea house. His uncle secretly handed him a secret recipe for a palace drink from the imperial tea room. According to the secret recipe, the small vendors made sweet-scented osmanthus and sour plum soup for sale, which was highly sought after by the people in the capital. Therefore, the merchant asked fellow Hanlin scholars to name it "Jiulongzhai". According to the "Yanjing Chronicles" published in the 32nd year of Guangxu's reign: "The sour plum soup is boiled with sour plums and rock sugar, and mixed with rose mignonette ice water. Its coolness makes the teeth vibrate. Qianmen Jiulongzhai is the best in Kyoto." Fang Junyi, a Daoguang Jinshi, also wrote in his "Miscellaneous Memories of Chunming": "The thirst-quenching plum soup has been chilled for a long time and is more famous than the Nine Dragons."
Despite its profound historical background, as the Qing court With the decline of the country, various places fell into warlord melee, and Jiulongzhai Sour Plum Soup fell into a trough. If not for the intervention of the Yanjing Group, Jiulongzhai, a century-old brand, might have slowly disappeared.