Soy sauce brewing technique (Xianshi soy sauce brewing technique) is a traditional technique popular in Hejiang area of Luzhou City, Sichuan Province, and one of the national intangible cultural heritages. Xianshi soy sauce brewing technique "began in Han Dynasty, flourished in Tang Dynasty, and prospered in Qing Dynasty". Xianshi soy sauce uses soybean as the main raw material and is brewed by traditional techniques, which is fundamentally different from other brewing techniques. Soy sauce has the qualities of "rich soy sauce aroma, brown-red color, clear body, delicious taste, hanging bowl without sticking to the bowl, and long storage without deterioration". The traditional brewing technique of Xianshi soy sauce contains thirteen processes, including screening raw materials, soaking soybeans, steaming and stewing soybeans, cooling soybeans, mixing flour, natural koji, making salt water, transferring koji into the tank, sun exposure and night dew, natural oil immersion, exposure to the sun and concentration, filtration clarification, sterilization and canning. In addition to the process, the time for brewing soy sauce is also important. The brewing of soy sauce starts from the beginning of spring, and the vat is turned over at the beginning of summer, checked at the beginning of autumn, and defrosted at the beginning of winter. Each solar term is an important node in the brewing of soy sauce. After another beginning of spring 3 to 5 years later, a vat of soy sauce is considered to have completed the process. After the whole soybeans are steamed, the process of making koji with natural wild fungi is very important. It has high requirements for temperature, humidity, and time nodes. The temperature of koji making should be kept at around 25. It cannot be too high or too low. All the workers' time has to be spent on making koji. Xianshi's soy sauce brewing skills have a long history, and the workshop architectural style remains the same, with a profound historical heritage. It is a physical carrier of traditional soy sauce hand-brewing skills and has high historical and cultural value. In January 2007, the traditional brewing technique of Xianshi soy sauce was listed in the first batch of intangible cultural heritage list of Hejiang County; in 2007, the Xianshi soy sauce production base was approved by the People's Government of Sichuan Province to be included in the second batch of intangible cultural heritage productive protection demonstration bases; on November 11, 2014, the soy sauce brewing technique (Xianshi soy sauce brewing technique) was approved by the State Council of the People's Republic of China to be included in the fourth batch of national intangible cultural heritage list, project number -154.