"The bottom whiskers are diverted by the water, and the summer is cool to Yanshan. The sound of copper bowls in the street, an ou of ice water and plum soup. Reciting this poem by Hao Yixing of the Qing Dynasty, "The Words of Bamboo Branches in Dumen", it seems to reproduce the streets and alleys of old Beijing, the stall selling sour plum soup with a crescent moon blade indicating that it is boiled at dawn, and the stall owner constantly knocks on the small copper bowl to drink and sell the sour plum soup; and the buyer is expected to quench his thirst, smell the cool feeling, drink this sour plum soup with sour, sweet silk, and cold ice, suddenly feel cool and quench his thirst, and the heat is completely gone.
Sour plum soup is made by using plum as the main raw material, with rock sugar, osmanthus flowers, licorice, roses and other accessories, boiled in a copper pot or casserole pot and then iced. The so-called ume is a dried product that selects an immature plum (green plum) and becomes a dark color after being smoked and dried. The "Compendium of Materia Medica" contains wumei as "smelling sour, warm, flat, astringent, non-toxic", and has a variety of medicinal effects such as lower breath, heat removal, peace of mind, and pain relief. Modern science proves that the nutrition of Wumei is rich in organic acids and minerals, although it is sour in the mouth, and even sour to make people shiver, but with sugar, coupled with the combination of water and ice, will achieve the balance of sweet and sour, stimulate the taste buds, remove heat and cool, and enjoy the purpose of body and mind.
Chinese has a long history of drinking sour plum soup, and the Southern Song Dynasty's "Wulin Past Events" mentions the "brine plum water" sold by Hangzhou restaurants, which is closer to sour plum soup. "Water Margin" wrote that after Ximen Qing met Pan Jinlian, he was overwhelmed and went to the Wang Po Tea House to find out the details. "The queen mother came out and said, 'Great official, eat a plum soup?' Ximen Qingdao: 'Preferably, add more acid.' The princess made plum soup and handed it to Ximen Qing with both hands. "Dream of the Red Chamber" also mentions sour plum soup: one day, Baoyu was beaten by his father Jia Zheng with a board "pain in the buttocks, like a needle picking a knife digging", he could not eat or drink, just when the people around him were anxious, the raider said that Baoyu "only shouted thirst, want to eat sour plum soup."
The famous sour plum soup is the "Chinese time-honored brand" Beijing's Xinyuan Zhai and Jiulong Zhai. Xinyuanzhai was opened in the fifth year of the Qianlong Dynasty (1740), the original site was outside the mouth of the Wenming Hutong of dongliulichang, and now there is a large factory in the Changping Industrial Park in Beijing. Its sour plum soup "fine selection of ingredients, heavy ingredients", using the formula of the Qing Palace Imperial Tea House, and often hired Qing Palace officials to taste when boiling, solicit their opinions to improve and enhance, so it has the reputation of "palace treasure".
Kowloon Zhai also opened its shop during the Qianlong period of the Qing Dynasty, and after three relocations, it was finally moved to Qianmen Street. The Miscellaneous Records of the Dynasty and the Wild since Daoxian says: The meitang maker in Beijing is "the most prestigious to the Liulichang Xinyuan Zhai and the Kowloon Zhai on Qianmen Street". The "Miscellaneous Records of Chunming" by Fang Junyi, a jinshi in the Light Years of the Qing Dynasty, also praised: "Quenching thirst plum soup has been cold for a long time, and it is famous for no more than nine dragons." "Except for a period of closure, every summer, the sour plum soup of this shop is boiled and cooled every morning, packed in a large blue and white porcelain jar, surrounded by ice cubes, and sold with wooden tips.
The key to making sour plum soup delicious is to control the ratio of plum, sugar and water (ice), which is what we usually call the sweet-sour ratio. Too sour will prick the teeth, too sweet will be greasy, too much water (ice) will dilute its inherent flavor. Only sweet with sour, sour with sweet, plus the right amount of spices to enhance the taste, is just right. Liang Shiqiu's "Yashe Talks About Eating" talks about the success secret of Xinyuan Zhai's boiling of sour plum soup: "There is more rock sugar, the plum juice is thick, and the water is less, so the taste is thick and salty. The entrance is cold, sweet and sour, and it is contained in the mouth like pure mash, and it is reluctant to swallow. "It's a matter of knowing.