Wuyuan vinegar, also known as black vinegar, one of the famous products of Qinghai, has a brewing history of more than 300 years. It is an integral part of the commercial culture of the ancient city of Tanjur. Its traditional production technology has been included in the second batch of intangible culture in Qinghai Province. Directory of heritage protection. Wuyuan vinegar is made from green glutinous rice and bran as the main raw material. More than 100 kinds of Chinese herbal medicines such as grass fruit, Daxiang, soybean meal, alfalfa and Codonopsis are added. After more than 60 production processes, the texture is thick, the flavor is rich, and the winter is not. Frozen vinegar that is not rotted in summer.