The Internet is full of opinions that pressed oil is healthy and safe, while extracted oil is harmful. In fact, no matter which process is used, only crude oil is obtained, also called crude oil. "Soil-pressed oil" is such an oil, but from the perspective of modern food science, this kind of oil cannot be eaten directly. It has too many harmful substances and is very harmful to the body.

In fact, pressed oil is also refined. After refining, it is basically pure oil just like extracted oil. As mentioned before for leached oil, organic solvents are highly volatile, and the residual amounts in the finished oil are far from harmful. Edible oil in modern technology, a complete production process, must remove impurities in the oil through refining. The result is a clear, light-colored refined oil that meets different grades of oil standards before it can be marketed.

So you can refer to these two points when buying oil:

Process: pressing or leaching, depending on what you want to buy. As long as it meets the technical quality standards for edible oil promulgated by the state, it is a safe edible oil that can be consumed with confidence.

Grade: With the exception of olive oil and specialty oils, cooking oil grades are classified by degree of refining. For example, soybean oil, corn oil, peanut oil... are generally divided into four levels. The higher the level, the higher the degree of refining, and the more suitable it is for cooking at high temperatures. The first-level refining degree is the best. Generally speaking, first- and second-level oils can be used for high-temperature cooking; third- and fourth-level oils are not suitable for high-temperature heating and can be used for soups, stews, stuffings, etc.

As for "oil extraction", I firmly oppose buying it with both hands. In my popular science, I try to present both the good and the bad sides, and then everyone can choose according to their own situation. However, "squeezing oil from the soil" is one of the few things that I will clearly tell you that I am opposed to. In the next article, the problems and hazards of "soil-pressed oil" must be taken out and written separately, as the last popular science article in the edible oil encyclopedia series .