Take a look at the color: Generally, high-grade oils are light in color, while low-grade oils are dark in color (except sesame oil). The color of oils of the same grade is slightly different due to different varieties.

Second look at the transparency: Generally, high-grade oil has good transparency and no turbidity.

Thirdly, check whether there are any sediments: high-grade oil has no sediments and suspended solids, and has low viscosity.

Fourth, check whether there is stratification: if there is stratification, it is likely to be adulterated mixed oil (sesame oil is more adulterated).

Five smells: Each variety of oil has its normal unique smell, but no sour or odor.

Six checks: Carefully check the trademark of small packaged oil, pay special attention to the shelf life and factory date. Pay special attention to those that have no factory name, no factory address, and no quality standard code.