https://www.thedailymeal.com/1353224/best-oil-seasoning-cast-iron-skillet/

Repeatedly oiling and heating a cast-iron skillet gives it a nonstick surface due to a chemical process called polymerization. In the context of seasoning a cast-iron skillet, polymerization occurs when the oil is exposed to high temperatures, subsequently breaks down, and forms a bond with the metal. This process is more successful if the oil you use is high in unsaturated fat. There are many vegetable oils that are rich in both mono and polyunsaturated fats, but avocado oil outperforms others due to its higher smoke point.

The smoke point of refined or regular avocado oil falls between 500 and 520 degrees Fahrenheit. By contrast, grapeseed oil, a more commonly recommended seasoning oil, is 420 degrees Fahrenheit. That’s high, but it’s still significantly lower than the smoke point of unrefined or extra virgin avocado oil, which is 482 degrees. 

A higher smoke point causes polymerization to occur at a much slower rate, which is precisely what yields a more solid nonstick coating. As a result, your cast iron will stay seasoned for far longer.

I have always used peanut or vegetable oil on my cast iron.

  • mick@lemmy.ca
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    1 year ago

    Avocado oil might technically be the best, but it’s also 5 times more expensive than peanut or vegetable oil. I use peanut as well and think it’s good enough.

  • waldenA
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    1 year ago

    I’ve never tried avocado oil, but Flaxseed Oil used to be all the rage. It made a beautiful seasoning that chipped off within a year. I’m more of a Crisco type person.

    • mick@lemmy.ca
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      1 year ago

      Yeah, Crisco’s good too. We bought some for baking and I tried it once. Worked just as well as peanut oil.

      • Usually_Lurker@artemis.camp
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        1 year ago

        Team Crisco!!! If it was good enough for Grandma, it’s good enough for me!! Also it’s Grandma’s pan so she started it.

  • iesou@lemm.ee
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    1 year ago

    Avocado oil, in America at least, can’t really be trusted. Usually has lots of impurities is rancid and often times contains other oils. 2020 study from UC Davis

    Edit, I use peanut or “vegetable” oil. Really anything with a high smoke point will do the job.