There is quite some contrary information out there on using flaxseed oil to season cast iron equipment. Some examples from the Seasoned Advice website:

This answer (67 upvotes; posted 10 years ago) says:

You want flaxseed oil (which incidentally has a low smoke point) but a high iodine value, allowing it to polymerize readily.

Whereas this answer (27 upvotes; posted 2 years ago) says:

Don't use flaxseed oil, it's one of the worst.

Using flaxseed oil is further substantiated in the posts above and references linked, but I am not sure how to evaluate these contradicting claims. Anyone has any idea?

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    +1. I have been following the pro flaxseed oil instructions and failed, so would also like to know.
    – Dave
    Commented Sep 2, 2021 at 21:51
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    @moscafj Thanks but this is exactly the same post I linked above. This has an answer specifically recommending flaxseed oil, whereas the other post I linked above suggests the opposite. My question is about how to decide if flaxseed oil is a good or a bad idea.
    – user95399
    Commented Sep 2, 2021 at 21:52
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    I think your question is essentially a duplicate of the one moscafj links to. Note that the accepted answer on the pro-flaxseed oil says to avoid low smoke point oil (which describes flax oil). So In a way you're asking about the contradiction between this and this. I'd count the voting on those answers as an answer to your question.
    – AMtwo
    Commented Sep 2, 2021 at 22:24
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    If you do have questions about seemingly contradicting answers on a question both being well up voted, that's a great question to ask on Seasoned Advice Meta.
    – AMtwo
    Commented Sep 2, 2021 at 22:25
  • Hi, I understand the wish to know some kind of actual truth. All you can get on the site though, is the opinion of different people, ordered by popularity through the voting system. You already know which opinions exist, and that both have their proponents. Asking the same people to vote on the same opinions again is not going to get you any closer to a truth.
    – rumtscho
    Commented Sep 6, 2021 at 10:38

1 Answer 1


The way to evaluate the contradictory claims is to find a source who did careful, controlled-variable testing of flaxseed oil vs. other oils for seasoning cast iron. Neither of the sources cited in those questions is such a source; one is a chemist who arrived at flaxseed based on chemical knowledge but didn't compare with anything else, and one is a publication that rejected flaxseed oil based on reported problems, but didn't share their methods or apparently do direct comparison testing.

My personal experience with rescuing a couple cast iron skillets was that flaxseed works quite well, producing a hard, nonstick surface. I also use the heat-and-wipe method rather than the invert-in-the-oven method. But ... I didn't try to compare it with anything else.

So, did anyone?

The Kitchn & Cook's Illustrated tested and liked Flaxseed oil, but didn't test it head-to-head with any other oils. In fact, the Kitchn says:

There is one school of thought out there that says it’s not the flaxseed oil but the method that makes this work. In other words, season a cast iron pan six times for 18 hours with any oil and you’ll get a hard, slick surface.

Also, note the number of preconditions and steps in their method; certainly failures with flaxseed could certainly be a result of violating one or more of those "rules".

While one can find any number of comparisons of oil for seasoning, you'll find that none of them do any scientific testing. Grapeseed oil is also popular, as is refined coconut oil. The usual sources of science-based data for cookware are mute on this topic because cast iron is rarely used in professional kitchens and never in industrial-scale food prep.

So if you want The Answer on which is the best ... you're going to have to arrange testing yourself.