Sour plum soup is a traditional summer drink in old Beijing. In the hot season, most people will buy dark plum trees and cook them themselves (they can also use red bayberry instead of dark plum trees), put some sugar in it to remove the acid, and drink it after cooling it. Vendors also do this small business. There used to be old people outside Hadmen who often held ice cups (two small copper bowls) in their hands to make a noise to attract attention and sell them while walking. Source Sour plum soup has been a good summer drink in ancient times. In the Qing Dynasty, the imperial dining room was improved into a royal drink, such as the so-called "Shigong Plum Jian". Because of its effects of removing heat and cooling, relieving heartache, eliminating phlegm and relieving cough, dispelling epidemic diseases, and promoting saliva and quenching thirst, it was praised as "the royal plum soup made by the Qing Dynasty" and was later introduced to the people, so in the streets and alleys, at the door of dried and fresh fruit shops, vendors selling sour plum soup can be seen everywhere. A crescent halberd (indicating that it is cooked at night) is placed on the stall, and a sign that says "Iced Hot Water Sour Plum Soup" is hung. The stall owner held a pair of small bronze bowls and knocked them from time to time to make a clank sound. Road People's Congress is hopeful that Mei has quenched her thirst and feels cool when she hears it. After eating a bowl, the heat completely disappears. At that time, the operators of sour plum soup not only sold them on the streets and set up stalls to sell them, but also had many shops mainly focusing on sour plum soup. For example, the "Qiu Family" on Tianqiao, the "Luyuzhai" on Xidan Pailou, the "Yuyuanzhai" on Mending Street in Dong 'an, and the "Jiulong Zhai" outside Qianmen are all famous. Currently, only the "Xinyuanzhai" on the south of Liulichang Road at that time remains. <br />Our country has had sour plum soup long ago. The "Tugong Plum Jian" recorded in ancient books is one of the oldest sour plum soup. The "marinated plum water" mentioned in "Old Things in Wulin" of the Southern Song Dynasty is also a cool drink similar to sour plum soup. The sour plum soup we are drinking now is a refreshing drink made by the imperial dining room of the Qing Dynasty for the emperor to cool off and quench their thirst, and was later spread to the people. It was 150 years earlier than the soda introduced to our country from Western Europe.
