Beijing Erguotou is named after the brewing process. In ancient times, the utensil used for steaming wine was a tin pot, also known as a sky pot. The sky pot consists of two parts: a steamer pot and a cauldron pot. Fermented mash is spread in the steamer pot, and then cold water is poured into the cauldron pot. After the mash in the steamer pot is heated, the wine vapor evaporates and condenses into wine when it meets the cold water at the bottom of the cauldron, which is led out with a pipe. After the temperature of the cold water in the cauldron pot rises, it is necessary to replace it with another pot of cold water to lower the temperature and continue to condense the wine vapor into wine. Since the wine condensed from each pot has obvious differences in aroma and taste, and the first half of the wine condensed from the second pot has both a mild taste and a mellow aroma, it is named "Erguotou" and has been passed down to this day. The traditional brewing technique of Beijing Erguotou originated in the Yuan and Ming dynasties and took shape in the 19th year of the Kangxi period of the Qing Dynasty (1680). It has been passed down for nine generations since the Zhao family of the Kangxi period of the Qing Dynasty, and is an important representative of the history of Beijing brewing. After 1949, Beijing Erguotou entered a period of rapid development; in 2008, the brewing technique of Beijing Erguotou was selected into the second batch of national intangible cultural heritage protection list. In the more than 300 years of inheritance history of Beijing Erguotou traditional brewing technique, brewers have continuously innovated brewing techniques by looking, smelling, tasting, modeling, kicking, etc., and passed on brewing techniques through oral transmission between masters and apprentices. Among them, the old five-steamer fermentation, mixed steaming and burning, and watching the flowers to receive wine are all mysterious skills of brewing technicians of all generations. The wine receiving method of pinching the head, removing the tail, and taking the middle section is the first creation of Beijing brewing technicians, which is also the origin of Erguotou and a milestone in the development history of Chinese liquor. Beijing Erguotou traditional brewing technique is an important carrier to show the folk customs and food culture of Beijing, with distinctive local characteristics. It concentrates on the essence of Beijing's 800-year history of liquor and is the memory of Beijing city.