In the past, there used to be an old man outside Hade Gate. He would often hold ice cups (two small copper bowls) in his hands, make noise to attract people's attention, and sell them while walking. Sour plum soup has been a great summer drink since ancient times. In the Qing Dynasty, it was improved by the imperial dining room and became the royal drink of the palace. The so-called "Shigong Mei Jian" is this. Because of its functions of removing heat and cooling, relieving pain, dispelling phlegm and relieving cough, warding off epidemic diseases, producing body fluid and quenching thirst, it is known as the "Emperor-made Black Plum Decoction, a rare treasure of the Qing Dynasty". Later, it was introduced to the people, so vendors selling sour plum soup can be seen everywhere in the streets and alleys, and at the entrances of dried and fresh fruit shops. A crescent halberd is placed on the stall (to indicate staying up late at night), and a sign that reads "Ice Hot and Sour Plum Soup" is hung. The stall owner holds a pair of small bronze bowls and knocks them from time to time to make a clanging sound. Passers-by can expect that the plum blossoms will quench their thirst and feel cool after hearing the sound. After one bowl, the heat will disappear. At that time, operators of sour plum soup not only hawked it along the streets and set up stalls to sell it, but there were also many shops selling sour plum soup. Such as the overpass "Qiujia", the Xidan Archway "Lu Yunzhai", Dong'an Mending Street "Yu Yuanzhai" and so on. China has had sour plum soup for a long time. "Tugong Plum Jian" recorded in ancient books is one of the oldest sour plum soups. The "braised plum water" mentioned in "Old Martial Arts" of the Southern Song Dynasty is also a refreshing drink similar to sour plum soup. The sour plum soup that people drank was a drink made by the Imperial Kitchen of the Qing Palace for the emperor to relieve summer heat and quench his thirst, and later spread to the people. It is 150 years earlier than soda was introduced to China from Western Europe.
After soaking the black plums, add rock sugar, honey, and osmanthus and fry them together. After chilling, it becomes sour plum soup.