In ancient summer, how did the rich or the palace keep food? If there is such a thing as an ice kiln, where did it come from?

In the Book of Songs, it is recorded that in December, ice cubes were cut, and in the first month, ice rooms were hidden.

Man seems to have a long history of using ice to serve himself. Li Zhou has a record of "Bing Jian". According to research, the so-called "ice guide" is a container used to hold ice cubes and put food inside in summer. Well, the "ice guide" should be the earliest "refrigerator" used by human beings. "Wu Yue Chun Qiu" also records: "Gou Jian's trip is also to rest and stay in the ice kitchen." The "ice kitchen" mentioned here is the place where the emperor prepares food in summer, so it is also called "cold palace". "Lenggong" has the functions of modern refrigerator and air conditioner.

The ancients also applied "refrigerator" technology to production and transportation. In the Ming Dynasty, Huang Province wrote in the Book of Fish that fishermen often "raised white scale fish with ice" and transported them to distant places, which was called "chilled fish". From this point of view, at the latest in the Ming Dynasty, the ancients in China widely adopted the storage method of "ice preservation".

In ancient times, ice storage was said to be a sacrifice to the gods to prepare for summer, and an official named "Lingren" was also equipped to manage the ice bank. Every winter, people cut the ice in the river into pieces, put it in the cellar and seal it. In order to prevent air from entering, the ice can be kept until the hot summer. This method has always been like this. The Forbidden City in the Qing Dynasty has five ice rooms and nearly 30,000 places for storing ice cubes in ancient times or perishable goods in summer. Its function is similar to today's "refrigerator", and this method has been used until the late Qing Dynasty.