He Yongzhi, president of Chongqing Hotpot Association, told reporters that old oil and old yeast are the same in wine fermentation. Old oil can keep the original flavor of old hotpot and is a unique raw material of Chongqing hotpot. Old oil can only be used after three processing procedures: precipitation separation, water purification and high temperature purification and sterilization. The treated old oil is not pathogenic or contagious, but its fragrance remains unchanged. Hotpot oil is a mixture of animal oil (butter and lard) and vegetable oil (vegetable oil, salad oil and sesame oil). At present, among the three existing technologies for treating old oil in Chongqing, two purification technologies (water purification and high temperature purification) are carried out at high temperature (100℃), and ordinary bacteria, fungi, spores and viruses can be inactivated in 20 minutes at 80℃ to 100℃.

In order to eliminate people's "fear" of old oil, Chongqing Hotpot Association and Chongqing Health and Epidemic Prevention Station jointly formulated the production standard of old oil. Tested by relevant departments, all indicators can reach or exceed the national health standards.

It is understood that in order to further promote the development of hot pot enterprises in Chongqing, Chongqing Hot Pot Association spent 500,000 yuan, with the help of Chongqing Municipal Science and Technology Commission, and cooperated with five scientific research units, including the Third Military Medical University and Southwest Agricultural University, to establish the industry standards for hot pot old oil, soup and dishes. The hot pot association said that the old oil label will be announced soon.