Beijing Longmen Vinegar Factory was founded in the 25th year of Jiaqing in the Qing Dynasty (1820). The original vinegar workshop was built in Longguan County, Hebei Province (now belonging to Chicheng County). The small town is surrounded by mountains and rivers. There are arches on the mountain. The shadow of the arches shines into the river water and there are fish in the water, so it is named Longmen. Another meaning is that a carp jumps over the dragon gate, hoping to seek wealth in the water. The Qi family is both the owner and the shopkeeper. At first, Longmen Vinegar House was a workshop that mainly brewed pots and brewed wine, and also made vinegar. At that time, the Daqu produced by Longmen itself was made into vinegar, except for the use of soju, which was produced once a year. It has 300 small vinegar tanks. The vinegar mashed ivory made from it must be stored for one year first, and then sold as soon as it is poured. Since the longer the vinegar mashed ivory is stored, the better the flavor, so the gantry product has a mellow texture, rich aroma and sour taste. It is soft, clear and transparent, and is loved by everyone and is praised by people as "longmen jealous".