Hello, what I know at present is that the first grade is the highest among the oil grades. As far as sesame oil is concerned, the quality of the first-grade oil will be very clear and there will be no impurities. I think it's a gimmick, and generally speaking, the authentic ones are made in Bama, Guangxi, where there is only one big factory, and the others are small workshops run by the people. The key is to pay attention to the origin and factory, I hope it will help you.