Picture of Best Way to Season Cast Iron Pans - Flax Seed Oil
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

Picture of 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.
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cchubb3 years ago
Why does the "no soap" mantra keep coming up. I've been cooking on cast iron all my life and I use Ultra Dawn on mine after every use, usually using either a regular sponge, or one of those twisted stainless pads if it's really caked on crusty stuff.

I usually season it every two or three years, not because it needs it regularly but because it usually suffers some kind of abuse like having something salty left in it (usually soy sauce) overnight or if the patina gets too thick and I have to clean it in the self-cleaning oven and then reseason it.

I will agree that you never want to use a brillo or other abrasive cleaner (comet, chore boy, etc.) on your iron. It's not as much the metal but the "soap" is much too aggressive. If whatever is in there is that caked on, just soak overnight in the sink, clean in the morning and wipe dry without allowing water to pool on it.

Me, I just use olive oil to season it. Flax oil is "edible" but so is mineral oil and I wouldn't want to use that in my pan.

One thing that looks different from my pans is that the pans in the picture don't appear to have a machined inner bottom, they look more rough, direct from the mold. Perhaps that's just the camera, but when the bottom of your pan isn't flat, you need to fill all of the nooks and crannies with oil to keep stuff from sticking. You have to look a lot harder to find pans with machined bottoms.

None of this comment is meant to be disparaging to the original poster and I'm sure your process works well for you and your pans. But please be aware that too many people are scared away from iron because they think it's too temperamental. I put my iron pans and dutch oven into harms way (melting candy sugar, using soy sauce, scrubbing with dish soap, sauteeing directly on the grill, frying potatoes, caramelizing pork butts, all kind of hot, acidic, salty food and they come through it just fine with little more than an oil wipe down before use and another if it's looking "tired" after washing, followed by a quick heat on the burner to about 300 degrees, then let it cool off in place.

the surface texture is likely you have newer cast iron pan they have a rougher look than the older pans which had an almost smooth appearance to them. unsure the reason for the change.

tubeist-d cchubb7 months ago

Mineral oil is 'edible' but indigestible; which makes it a good lubricant for constipation: that stuff ain't going nowhere but out. It also doesn't polymerize. Period. It cannot be used for seasoning.

Olive oil is fine, but people should bear in mind that the smoke point of olive oil varies widely with cold-pressed, virgin, extra virgin, extra-virgin acidic, etc., and it's slow to polymerize to get to a film condition. Flax oil is best for people who are seasoning their first pan. I happen to use the similarly-behaving walnut oil because I cook with it a lot anyway. Once you have a pan with a good ol' coating, re-seasoning goes well on the old film without much worry.

gregs12 tubeist-d6 months ago

thanks for the explanation of WHY not to use mineral oil

BearM gregs1225 days ago
Mineral oil is ingestible, I've been using it for years on my cast iron. I'm not sure where people come up with the nonsense they spew? As a side note: mineral oil is great for constipation; a tablespoon at a time. Not as a thin coat on cast iron!
BearM tubeist-d25 days ago
Soap does strip away some of the seasoning. It is best to put a little bit of water in the bottom of the pan and heat it into it bubbles over low heat. Once bubbling, dump the water and wipe out the pan. Also, while it's still warm wipe a thin coat of oil in the pan. It's ready to go for the next time
I agree with most of what you say here, except the soaking part. If I have stuff that is so stuck in (frequently), I simply either run straight hot water over it and set it aside for a few minutes, or if it is bad, heat it on the stove top, add screaming hot water and use the metal spatula to scrape the hard to get stuff off. After that, a hot water rinse, reheat and wipe the remaining water out with a paper towel and done. The longer soaks can tend to make it rust if it has any areas that aren't as seasoned as they should be. (or they can make my grandmother roll in her grave, as she firmly believed that too much water on cast iron ruined it)
Really, the #1 secret to having a non-stick cast iron pan is to buy one with the machined bottom. I can't stress that enough. Griswold and Wagner made awesome pans and you can still buy them on eBarf for less than the cost of new a sand-cast Lodge with a surface that looks like craters on the moon.

The machined surface I am talking about is on the inside, where the food sits. Not the bottom where it sits on the stove. If the inside looks like asphalt instead of machined steel you are going to need a lot of oil to keep it stick free. If it's really flat, like to within 1 or 2 thousandths, it's not going to need much oil.

Hey, I'm happy people are using cast iron instead of some fancy ultra-slick junk that wears out in a year.
Everyone from poets to politicians will agree that language is an imprecise medium.

Compare the pictures I posted of pans with machined cooking surfaces with the pictures posted at the top of the instructable. The pans at the top don't have a machined cooking surface, they are exactly as they came from the molds, but possibly sanded flat on the stove side to sit flat on an electric burner. Granted, one has the "grill bars" that help lift greasy food up out of it's grease (and are great for pork chops or burgers), but the others are just sand cast.

I wanted to buy a nice pan for my step brother's house warming and can't find anyone still selling machined pans brand new. I had to buy a used one from eBarf and clean and reseason it myself. It was still cheaper than a new one. (But shipping wasn't cheap...)
Then I refer you to my original post in which I said "machined inner bottom".
I know of what you speak with the cast iron pans not being finished with a milled flat smooth surface on the inside. I am now 61 when I was in my teens my mother had a cast iron skillet that had a machined inside surface. It was wonderful! Since that time I have never seen one like it. About a month ago, on your and my favorite site "EBARF", I found a unique cast iron skillet that was made as an electric skillet. The brand of the skillet is "Country Charm" mfg by The House of Webster in Rogers, Arkansas from about 1953 until 1997, which is no longer in business. Unfortunately they did not machine smooth the cooking surface, it is typical sand pitting which resembles the surface of the moon. I am going to take it to a local machine shop to have them turn machine flat the surface, like a disc or drum brake, the inside if its not too expensive then season it. Any thoughts?

Thanks, I forgot about the metal spatula. It should be your first choice with cast iron, both for cooking and cleaning. Probably because I haven't been able to find one worth a darn in years at the local stores. I'm not going to drop $50+ on something special at Williams Sonoma, but the proliferation of non-stick cookware has made metal spatulas a bit of a rare thing. I just keep my eyes open at thrift stores, you can find some good ones there.

I just caramelized some onions and then roast a chicken in my dutch oven last night. Everything just popped out nicely except for some chicken skin that was burnt on. I worked late so I didn't get a chance to do dishes, so It's soaking in the sink now.
Just a suggestion if you have an IKEA near you. I found a great set of cheap metal cooking utensils there. I was having the same problem. I can't stand all of the plastic non-stick spatulas. They constantly melt and it just feels like you can't really ever get them clean.
Broom cchubb3 years ago
The "no soap" mantra is based on the fact that even a film one soap-molecule thick will prevent oils from latching on, and therefore will stop the "self-healing" process of blackened iron.

However, as long as pots are *thoroughly* rinsed in hot water, such films shouldn't form.

Since there's a risk in using soap, and little health risk in not using it (but otherwise following good black iron maintenance procedures), people say "no soap at all!". YMMV; sometimes I use soap for removing excess tar-like burnt oils, but usually I go soap-free on black iron.
BearM25 days ago
I just recently discovered Flax Seed Oil for seasoning my pans. It works GREAT!
JKPieGuy1 month ago

Is it normal for the first coat to come out kinda rough, and some-what splotchy in some areas? Oddly enough it's only happening on the inside of the pans. The outside it quite smooth with a darkened sheen.

jbaer854 months ago
do you also recommend flax oil to season clay stoneware? if so is the process the same?
gregs126 months ago

lard has been used since the beginning of cast iron.

thomasbandy3 years ago
I did the steps as above exactly as written, 5 cycles in the oven - the pans look great, a smooth matte finish, silky to the touch. I tried to fry some eggs as I do every morning, and they stuck LIKE CRAZY - I cooked them in coconut oil, as usual, and I'd built up a pretty good nonstick surface before I tried this, but it's like it has a 'stick' surface - even the tiniest bit of egg white glued like cement to the surface, and I have to scrub it off with a copper scrubber. What could I have done wrong? I used very thin coats of the same organic flax oil...

Egg albumin and milk casein can be crazy adhesives. In fact casein IS an adhesive for some wood and other projects. On a worn teflon pan, even without discernable scratches, I can often have egg-sticking problems if I don't use a bit of oil.

The coconut oil is a surfactant, is was dissolving and softening you new seasoning.
I was always taught to heat the pan first, then heat the oil, butter, grease, etc. THEN put the eggs in. And always have enough of your oil, butter, etc. in the bottom of the pan that the eggs "float". We always fried the bacon first, then the eggs. Yum!

I just had to let you know that your "description" of your problems was really funny. Actually LOL'd. :-) Maybe the coconut oil is not good for seasoning. I used canola and it worked well for me.
atnola8 months ago

Ran into a snag on this step. After completing the application of 2 solid hard coats on my Wagner's Dutch Oven, my 3rd attempt just resulted in pooling or beading of the oil on the surface (no matter how thinly I applied it). It seems that, after only 2 cycles, I'm left with a surface so slick that oil will no longer grab onto the surface enough to form a uniform film. Maybe because the inside of the pot is machined, and therefore smooth to begin with? I don't know… but two coats seems to be the limit here.

tubeist-d atnola7 months ago

For that, you have to make this a continuous-monitor process. Use an (oily) bit of paper towel or silicone basting-brush, and sweep lightly over the surface every few minutes. Every 10 minutes add a little more oil and sweep it around the surface. You need a feather-touch for this because you're messing with the underlying congealing oil.

sqky3 years ago
i have used a combination of olive oil and canola oil, and left in about 1 hour, and repeated about 4-5 times, it worked out well. just try to store it in a dust free area as it remains slightly sticky.

if you are to impatient you can use a cooking brush to reapply when still warm, just remove from oven and place on an old cutting board or plywood.

if you don't use your cast-iron often place it in a paper bag and then inside a plastic bag, this is how i store my dutch oven when its not camping season.
doczod sqky3 years ago
Olive oil will leave the pan a little sticky. If you use just corn oil or vegetable oil, it won't be as sticky.
rapier1 doczod3 years ago
Olive oil doesn't have to leave the pan sticky. If it is sticky they you just haven't heated it long enough to achieve full carbonization.
tubeist-d rapier17 months ago

You don't want carbonization, and that is not what seasoning entails. The oil is polymerized, and somewhat oxidized into a tough, plastic-like finish with a low surface energy, not unlike teflon: there are no strong chemical 'loose ends' for crud to attach to. Flax oil, and the similar walnut oil, have good oxidation and crosslinking properties for seasoning.

atnola sqky8 months ago

No offense, but… this is terrible advice! Never should either Canola oil or olive oil be used to season cast iron. These oils will never truly solidify, which is why your pots were left with a sticky finish. Always use Flax Seed oil, if you want a perfectly smooth and durable finish.

can black seed oil be used for frying ?

nottauser3 years ago
I just used my big black skillet for the first time since a friend gave it to me and it worked great! I was amazed at the fact that it cooked my eggs so well without sticking and fried the potatoes to perfection ...now I just need to get a technique down on making fried potatoes like my folks used to when I was a kid and I can call my bachelor cooking skills completed. I love cooking but have a frankenstien approach to doing it, I realize it is a science and like to learn new things. I use grape seed oil to cook and wonder if that had something to do with the slick surface for cooking? Its got the highest level of viamin E even higher than safflower oil but both are great for healthy cooking although more expensive than other oils.
I cooked on medium and no smoke or sticking! INCREDIBLE! Better than a non stick pan and less worry about teflon flakes in the food.
when its time to re-season the pan I will appreciate having your instructable to refer to,Thanks so much!
When I lived in Sicily I learned from my Sicilian neighbors to always use grape seed oil whenever I wanted to fry something on high heat and fast. It has a high something-or-other and doesn't break down like other oils @ high heat. The food also doesn't absorb so much of the oil. I always fry my eggplant in grape seed oil. It comes out nice and crispy but still light.rave

Grape seed will work, Peanut oil adds more flavor.

You are right though, too many people try to use EVOO or something and end up with a smokey, oozy mess.

Make sure you rinse your potatoes at least 2 times to wash the starches off. If you are doing hash browns put them in a paper towels or a lint free cloth and squeeze the bejeeus out of them.

Removing starch and moisture is the key to super crispy and brown po-po-tay-toes.

This Instructable was the catalyst for me to buy Wagner cast iron from ebay. So much better than the big box Lodge stuff I was using.

ngio642 years ago
I did not have flax oil but I did have flax seeds. I ground them to flour and rubbed and rubbed until the pan had a slight wet look. Then I heated it for 1 hour, let cool, then ground more flax and rubbed it in again. I have done this 3 times and I am getting a really nice thin black surface. If it does not work I can always start over again with flax oil.
davijordan2 years ago
We just leave our skillet in the oven all the time. /great for fritattas and as a substitute pizza stone.
workislove2 years ago
This method is great! I found Cheryl's page independently a couple months ago and tried it on four old, inherited cast iron pans from my parents. The results have been amazing!

They are as good as or better than any non-stick pan I've used for cooking eggs and pan frying, and they have also been good for baking - I've made some great cornbread and pizza - great, even heating with no problems sticking.
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