Introduction: Best Way to Season Cast Iron Pans - Flax Seed Oil

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About: I've worked for Instructables off and on since 2006 building and documenting just about everything I enjoy doing. I am now the Creative Programs founder and manager for Autodesk and just finished building out…

I try to use cast iron cookware whenever possible.  It has excellent heat dispersion properties, life long build quality, and an inherent ability to cook foods with exceptional control at both high and low heats.  It works on all kinds of stoves, electric, gas, induction - even a fire pit while camping.  

The only snag about cast iron (if you can really call it that) is the seasoning process.  "Seasoning" cast iron refers to a process of building up some amount of material, which I'll call a finish on the pan that aids in cooking, creates a semi-nonstick surface on the pan,  and protects the cast iron pan against any possible rust.

There are lots of theories on seasoning cast iron, from complex rounds of heating and oiling with different types of vegetable and animal fats, to doing nothing at all.  Having tried many of these seasoning processes myself, I feel inspired to write about the flax seed oil method.  It's the most durable and straight forward seasoning process that I've found, and the science behind the process agrees.

Step 1: Flax Seed Oil

You can find flax seed oil in the refrigerator aisle at the grocery or health food store.  Flax seed oil is the edible version of linseed oil, a very durable, hard drying finish that painters and woodworkers have been using for a very long time.  As Cheryl Canter writes on her site: "The seasoning on cast iron is formed by fat polymerization, fat polymerization is maximized with a drying oil, and flaxseed oil is the only drying oil that’s edible."

What that translates to in practical terms is a durable finish, that even after just a few coats and short term heating results in a deep glassy black seasoning on the cast iron that has held up to months of my daily usage and cooking abuse.  

As with any other cast iron pan seasoning, You don't want to use soap on the pan when cleaning it, but with this method, I've found that using a mildly abrasive sponge when doing the dishes doesn't seem to affect the finish at all.

Step 2: Oil the Pan

Pour a small amount of the flax seed oil into the pan.  Less is more with this stuff, so shoot for more than just a few drops, but no more than a tablespoon.  Start with a teaspoon and go from there.  Then, using a paper towel or rag, spread the oil evenly throughout all the surfaces of the pan, including the bottom of the pan, the sides, and even the handle.

The pan should have a slight sheen to it, but no standing puddles of oil or thick areas of build up.  If you're really feeling inspired, use your bare hands to spread the oil around and envision yourself back in the old world.  Follow the rule of thumb for any other finish - shoot for a nice thin even coat.  You can always apply more, and, as you'll soon see, you will.

Step 3: Bake at 500F for 30 Minutes

Place the oiled pan inside a 500F degree oven for 30 minutes.  Some sources say to heat the pan for longer, but, if you've put on a thin coat of oil I've found that 30 minutes is plenty long enough.

The pan will smoke a bit during this process.  That is completely fine and natural, your oven will not catch fire.
The hot flax seed oil will smell a bit strange.  That is also completely fine and natural, the smell will go away.

PRESS ON! 

Step 4: Repeat 4 to 7 Times

Once you've "cooked" the pan for 30 minutes, remove it from the oven and let the pan sit until it's cool enough to touch.  When you're sure it's not still hot, reapply a thin coat of oil using the same method described in step 2, put it back into the oven and cook it for another half an hour.  

Keep repeating this process until you've gone through as many cycles as you'd like.  I've found that 4 to 7 rounds was enough to result in a semi-gloss, beautifully smooth, tough, black finish that is ready for use.

Step 5: Do All Your Cast Iron at Once

Final tip - do all your cast iron pans at once.  In my opinion, if you're gonna crank the oven up to 500F for several hours and make the house smell a little funny, you might as well make good use of it and season all your cast iron cookware at once.  The good part is that you won't have to repeat the process very often.  I've been going on the same seasoning session for several months now and they still look great.

Step 6: Use the Gas Grill

*update 1/30/12*

I now feel foolish for saying that this was the "best way" to season cast iron without mentioning this important tip that was brought up in the comments: if you want to avoid making your house smell like smoking oil - USE THE BBQ!

What a great idea - thanks to everyone who suggested this.  Next time, I'm definitely gonna use the grill.

photo attribution