According to legend, vinegar was invented by Heita, the son of the Wine Saint Du Kang in ancient times. Du Kang invented wine, and his son Heita did everything from carrying water to moving vats in the workshop, and gradually learned the wine-making technology. Later, after Heita made wine, he felt that it would be a pity to throw away the lees, so he stored them and soaked them in a tank. On the 21st, when I opened the vat, a scent that I had never smelled before hit my nostrils.

Attracted by the rich aroma, Heita took a sip. It tasted both sour and sweet, and tasted delicious, so he stored it as a "seasoning paste". Heita named this condiment "vinegar" by adding the word "You" to the twenty-first day.

Extended information:

In the book "Zhou Rites" written by Zhou Gong in 1058 BC, there is a record that "Xinren palms the five Qi and Qijing". Xinren is Zhou Officials of the royal family in charge of Wuqi and Qijing. The so-called "Wuqi" refers to the five stages of fermentation in the ancient Chinese wine-making process. The fermentation people must be familiar with the wine-making technology to brew vinegar.

The scale of the official system of Xiren was second only to wine and pulp at that time, which shows that vinegar and vinegar-related products played an important role in the emperor's daily dietary life. Because Shanxi people are jealous, people also call Shanxi people "Lao Xi". Special vinegar-making workshops appeared during the Spring and Autumn Period and the Warring States Period, and there are records of vinegar in The Analects of Confucius.

Baidu Encyclopedia-Vinegar