Chemistry of Cast Iron Seasoning: A Science-Based How-To

The post after this one on “black rust” describes why you should heat the pan before applying oil for seasoning. This helps the seasoning to adhere and makes the pan pleasantly black.

http://sherylcanter.com/wordpress/2010/02/black-rust-and-cast-iron-seasoning/


In a previous post, I illustrated how I cleaned and reseasoned an antique cast iron popover pan. This was my first attempt, and my seasoning technique was somewhat haphazard because I couldn’t find consistent, science-based advice. I used a combination of organic avocado oil and strained drippings from organic bacon. This worked pretty well on the popover pan, which doesn’t have a polished surface. But the smooth inner surface of a skillet showed an unevenness of color and texture, and the seasoning wasn’t hard enough. It was too easily marred by cooking utensils or scraping against oven racks.

I wanted to understand the chemistry behind seasoning so I’d know how to fix this, but there is nothing that addresses this issue directly. A Web page on cast iron posted by someone similarly obsessed with the science gave me two crucial clues, the phrases “polymerized fat” and “drying oil”. From there I was able to find the relevant scientific literature and put the pieces together.

The pictures below are both of the same antique cast iron skillet. The “before” close-up on the left is from a picture of the skillet in my previous blog post on making German Pancakes. I stripped the pan with oven cleaner and reseasoned it based on my new understanding. The “after” close-up on the right shows the result.

Griswold skillet closeups: old seasoning on left, new seasoning on right
Griswold skillet closeups: old seasoning on left, new seasoning on right

Start With the Right Oil (It’s Not What You Think)

I’ve read dozens of Web pages on how to season cast iron, and there is no consensus in the advice. Some say vegetable oils leave a sticky surface and to only use lard. Some say animal fat gives a surface that is too soft and to only use vegetable oils. Some say corn oil is the only fat to use, or Crisco, or olive oil. Some recommend bacon drippings since lard is no longer readily available. Some say you must use a saturated fat – that is, a fat that is solid at room temperature, whether it’s animal or vegetable (palm oil, coconut oil, Crisco, lard). Some say never use butter. Some say butter is fine. Some swear by Pam (spray-on canola oil with additives). Some say the additives in Pam leave a residue at high temperatures and pure canola oil is best. Some say it doesn’t matter what oil you use.

They are all wrong. It does matter what oil you use, and the oil that gives the best results is not in this list. So what is it? Here are some hints: What oil do artists mix with pigment for a high quality oil paint that dries hard and glassy on the canvas? What oil is commonly used by woodturners to give their sculptures a protective, soft-sheen finish? It’s the same oil. Now what is the food-grade equivalent of this oil?

The oil used by artists and woodturners is linseed oil. The food-grade equivalent is called flaxseed oil. This oil is ideal for seasoning cast iron for the same reason it’s an ideal base for oil paint and wood finishes. It’s a “drying oil”, which means it can transform into a hard, tough film. This doesn’t happen through “drying” in the sense of losing moisture through evaporation. The term is actually a misnomer. The transformation is through a chemical process called “polymerization”.

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. From that I deduced that flaxseed oil would be the ideal oil for seasoning cast iron.

As a reality check of this theory, I googled “season cast iron with flaxseed oil” to see what came up. The very first hit is a page written by a guy who seasons his cast iron cookware with linseed oil from the hardware store because it gives the hardest surface of anything he’s tried. (I’m not sure how safe that is; I don’t recommend it.) Below that were several sites selling traditional cast iron cookware from China, which they advertise as being “preseasoned with high quality flax oil”. I don’t know whether they really use food-grade flaxseed oil (which is expensive) or linseed oil from a hardware store. What’s significant is the claim. Seasoning with high quality flaxseed oil is something to brag about.

With this encouragement, I stripped one of my skillets and reseasoned it with flaxseed oil. As you can see in the picture above, the result was a dramatic improvement. The finish is smooth, hard, and evenly colored.

Seasoning Is Not Cooking: Different Principles Apply

The first time I seasoned a pan I chose avocado oil because it’s monounsaturated and doesn’t easily go rancid. It also has the highest smoke point of any edible oil, 520°F, so I could heat it in a 450°F oven without passing the smoke point. I knew that when cooking, you should never heat an oil past its smoke point because that causes the release of “free radicals”, which are carcinogenic. I was careful not to choose a polyunsaturated oil – and especially not an oil high in omega-3 fatty acids – because these are especially vulnerable to breakdown with heat and the release of free radicals.

Ironically, it’s for exactly these reasons that the best oil for seasoning cast iron is an oil high in omega-3 fatty acids – in particular, alpha-linolenic acid (ALA). Free radicals are actually what enable the polymerization. Drying oils, which produce the hardest polymers, are characterized by high levels of polyunsaturated fatty acids, especially the omega-3 fatty acid ALA.

The lard that was traditionally used for seasoning 100 years ago was much higher in ALA than fat from pigs today, because back then pigs ate their natural diet. Today they are raised on industrial feedlots and forced to eat grain, making their fat low in omega-3s.

Since lard is traditional but no longer readily available, many people substitute bacon drippings, but this is a bad idea. If it’s conventional bacon, you’re baking in carcinogenic nitrates. But even organic bacon is not good for an initial seasoning because it’s filled with salt.

The reason that Pam seems to work well in seasoning is that its main ingredient is canola oil, which is relatively high in ALA (10%), making it a “semi-drying oil”. Flaxseed oil, a drying oil, is 57% ALA. But it’s not a good idea to use a spray oil, no matter what oil it’s made with, because of its additives. You’re doing chemistry here. If you want good results, use pure ingredients.

Fat polymerization can be triggered or accelerated in a variety of ways. As best I can tell from my reading, the cast iron seasoning process is an example of “radical polymerization”. The process is initiated when something causes the release of free radicals in the oil. The free radicals then “crosslink” to form the tough, hard film you see in a well-seasoned pan.

So what is the “something” that initiates the release of free radicals in fat? Iron, for one thing. High heat, light, and oxygen, for some others. To prevent cooking oils from going rancid – i.e., breaking down and releasing free radicals – you need to store them in dark, tightly sealed containers in a cool location. To initiate or accelerate the release of free radicals, put the oil in contact with bare iron and heat it above its smoke point, which will cause even non-drying oils to release free radicals.

I haven’t defined “free radical” or “crosslink” because that gets into details of chemistry that you don’t need to understand to season a cast iron pan. All you need to know is that the molecular structure of the oil changes and becomes something else, something tough and solid. The process is initiated with the release of free radicals, which then become crosslinked, creating a hard surface.

Free radicals are carcinogenic inside your body, and also a cause of aging. So don’t ever heat oil you’re going to eat above its smoke point. If the oil starts to smoke, toss it out and start again. When you’re seasoning a pan, you’re not cooking food. By the time the seasoned pan comes out of the oven, there are no more free radicals.

The Recipe for Perfect Cast Iron Seasoning

The basic idea is this: Smear a food-grade drying oil onto a cast iron pan, and then bake it above the oil’s smoke point. This will initiate the release of free radicals and polymerization. The more drying the oil, the harder the polymer. So start with the right oil.

Go to your local health food store or organic grocery and buy a bottle of flaxseed oil. It’s sold as an omega-3 supplement and it’s in the refrigeration section because it goes rancid so easily. Check the expiration date to make sure it’s not already rancid. Buy an organic flaxseed oil. You don’t want to burn toxic chemicals into your cookware to leach out forever more. It’s a fairly expensive oil. I paid $17 for a 17 ounce bottle of cold-pressed, unrefined, organic flaxseed oil. As it says on the bottle, shake it before you use it.

Strip your pan down to the iron using the techniques I describe in my popover post. Heat the pan in a 200°F oven to be sure it’s bone dry and to open the pores of the iron a little. Then put it on a paper towel, pour a little flaxseed oil on it (don’t forget to shake the bottle), and rub the oil all over the pan with your hands, making sure to get into every nook and cranny. Your hands and the pan will be nice and oily.

Now rub it all off. Yup – all. All. Rub it off with paper towels or a cotton cloth until it looks like there is nothing left on the surface. There actually is oil left on the surface, it’s just very thin. The pan should look dry, not glistening with oil. Put the pan upside down in a cold oven. Most instructions say to put aluminum foil under it to catch any drips, but if your oil coating is as thin as it should be, there won’t be any drips.

Turn the oven to a baking temperature of 500°F (or as high as your oven goes – mine only goes to 450°F) and let the pan preheat with the oven. When it reaches temperature, set the timer for an hour. After an hour, turn off the oven but do not open the oven door. Let it cool off with the pan inside for two hours, at which point it’s cool enough to handle.

The pan will come out of the oven a little darker, but matte in texture – not the semi-gloss you’re aiming for. It needs more coats. In fact, it needs at least six coats. So again rub on the oil, wipe it off, put it in the cold oven, let it preheat, bake for an hour, and let it cool in the oven for two hours. The picture above was taken after six coats of seasoning. At that point it starts to develop a bit of a sheen and the pan is ready for use.

If you try this, you will be tempted to use a thicker coat of oil to speed up the process. Don’t do it. It just gets you an uneven surface – or worse, baked on drips. Been there, done that. You can’t speed up the process. If you try, you’ll mess up the pan and have to start over.

The reason for the very hot oven is to be sure the temperature is above the oil’s smoke point, and to maximally accelerate the release of free radicals. Unrefined flaxseed oil actually has the lowest smoke point of any oil (see this table). But the higher the temperature the more it will smoke, and that’s good for seasoning (though bad for eating – do not let oils smoke during cooking).

I mentioned earlier there’s a myth floating around that vegetable oils leave a sticky residue. If the pan comes out of the oven sticky, the cause is one of three things:

  • You put the oil on too thick.
  • Your oven temperature was too low.
  • Your baking time was too short.

It’s possible to use a suboptimal oil for seasoning, like Crisco or bacon drippings, and still end up with a usable pan. Many (most) people do this. But the seasoning will be relatively soft, not as nonstick, and will tend to wear off. If you want the hardest, slickest seasoning possible, use the right oil: flaxseed oil.


Editorial Note:

Many flax oils contain added ingredients to prevent rancidity, and it’s the tendency of this oil to go rancid that makes it so good for seasoning pans. Flax oil only works if it’s 100% pure flax oil with nothing added, so read the ingredients! People have reported mixed results, and this is probably why.

492 thoughts on “Chemistry of Cast Iron Seasoning: A Science-Based How-To

  1. Hi Sheryl,

    Cook’s Illustrated talked about your method, and it made sense. Thank you for demystifying this topic, I have been pulling out my hair over this. My dutch oven and three pans have been stripped and reseasoned three times without results (after doing internet searches all over the place), and the one time I ventured to use my dutch oven (with brickets) I had a rusty mess. What a cleanup job that was! By the way, you can strip cast iron in a self-cleaning oven, but have some extra elements on hand, I had to replace the element in my oven. Burned it out. I’d like to try the electrolytic method and see how that goes. Then I’ll try seasoning them one more time!

    Thanks,
    Bobbie

  2. Sheryl,

    I’ve been following your instructions for a while now, with very good results. I did have one minor suggestion that folks might find useful. I now use a microfiber hand towel for applying the flax seed oil. The benefits are fewer fibers left behind (than cotton or paper towel), a consistently even coating, and the thinest coating I’ve been able to get. This has resulted in a very glassy surface, looking more like enamel than the cast iron seasoning I’m used to.

    Also, on pans with years of seasoning which I do not want to strip, I sand (200 grt) down the existing seasoning in the pan to a smooth surface before washing, heating, and starting the flax seasoning treatment. I don’t sand down to metal, but I like to get rid of bumps before getting that glassy flax surface going.

    Thanks for keeping your blog up; I point all friends with cast iron your way. The shine these pans have is a bit of a conversation starter!

    -Henry

  3. Hi Sheryl,

    Thank you so much for this. I spent countless hours online looking for something like this. I seasoned the heck out of a new Lodge skillet using your technique, and eggs slide right out of it with just a little bit of oil.

    One question which I would love your thoughts on. I just got a new carbon steel wok and I tried to season it using a different technique, which didn’t work that well. Do you think your technique would work just as well on a carbon steel wok? Any reason not to try it?

    Again, thank you so much for this.

    Cheers,

    Brent

  4. Hi Sheryl,
    I’ve been cooking with and acquiring cast iron for years. I’ve always used Crisco shortening for seasoning with good results. After reading your article I took a Lodge preseasoned combo cooker that the coating had started to chip away(not sure why that happens sometimes) and wire wheeled the cooking surface down to bare metel. I followed your instructions with flaxseed oil and it came out awesome. I’ve seasoned it 6 times so far, and am going to do it 6-10 more times.

    Thanks for putting this info on the internet. Flaxseed oil is the way to go.

    Richard

  5. Thank you so much for all of this information. I’ve been searching the web for two days trying to find out the truth. There are so many conflicting reports, but once I read your site I knew this was going to work. I’ve been trying to season my grill plates for my outside grill. So I stripped them with a self cleaning oven, and I followed your process exactly. They look great, and they are really smooth. Will be great grilling on these. The only bad thing about this process is the smell in your home. Cleaning cast iron with a self cleaning oven cycle takes forever and smokes out the whole house. Seasoning it is also bad, but not as bad as stripping. I’m glad it’s over, and thank you once again for explaining this so well.

  6. Thanks for a great article. I found it really interesting and can’t wait to try your method. I have typically used the bbq to heat the cast iron so I don’t stink up my house. Did the flax stink above the smoke point?

  7. Is there any way to do this at a lower temperature for longer? Although I really want these results, my family cannot stand the fumes produced and my husband insists that they are toxic to breath – which could be the case. Any comments in this regards?

    Jenna

  8. I am totally going to try this method, once I find the suitable oil, but I have a question: can I also use it to season a cast-iron pan (a wok, in this case) that has a coloured enamel exterior?

  9. Hi
    I bought a new Lodge skillet that comes slightly dimpuled and with a black coating over the cast iron.
    Is there a better pan to start with—if not–do I need to get rid of the coating?
    Thank you for your help.

  10. I am old and did not know I was at the end of a long string of information.
    I went back to the top and read all the way down.
    My questions were already addressed—-so thank you to everyone.

  11. Hi there,

    I have three pieces on their second round in the oven after oiling them with flax-seed oil. I took the suggestion here and used a microfiber cloth to apply and to wipe. Things so far seem to be going well. I am heating at 500 – my place totally stinks but there has not been any visible smoke or setting off the smoke alarms as I have heard others have experienced. Perhaps the exceptionally thin coat accomplished by the microfiber cloth is the answer to not being smoked out. The heat is passed the smoke point – but alas no visible smoke – just stink. I assume that as long as I have heated the pans with flax-seed as far past the smoke point as my oven will allow, all will be well – smoke or not.

    Regards,

    Kate

  12. Thanks for really nailing down the science.

    I’ve been using sesame oil for seasoning cast iron for several years. My stovetop method has never produced the results you have gotten, but I think (based on trial and error) that sesame oil has some of the same qualities as flaxseed oil. (I.e., lotsa warnings about it going rancid, a low smoke point, and it seems to leave a dry hard coat on my pans (although you would surely tell me I’m applying it too thick).

    Whaddya think?

    Also, a question. If the lard of our ancestors worked well because of the pigs’ natural diet, then wouldn’t rendered fat from wild animals (my business partner is a hunter) work well too? I’m slowly making my way through a tub of duck fat (I recommend it for pilaf, btw), and may try it out for seasoning the pan.

    Best.

  13. FYI, the linseed oil usually sold at the hardware store is “boiled linseed oil” and has other (toxic) additives included to make it more shelf-stable, as well as to make it more useful as a paint aditive and standalone finish.

  14. Thanks for a great article! We’ve done 2 coats so far with the 3rd on in the oven as I type this, and so far, it’s looking great! I can’t wait to see what it looks like when we’re done!

  15. Thanks for this post. I have a newer cast iron pan which I didn’t know how to work with when I first got it, and I burned on some material that never fully came off so I always had a sticky pan. I was always afraid to try re-seasoning it myself. I just used oven cleaner for a few rounds, and then 5 rounds of flaxseed oil as you describe. I haven’t tried the coating yet, I’m a little worried it might be a tiny bit sticky, but it seems so much better than it used to be. I’m looking forward to trying it.

  16. Great article. I can’t wait to try it on a pan I just inherited. However, in hopes to clear up confusion from other posters, I would like to share the fastest and best way to season a NEW pan: take it out of the box and cook with it. DON’T automatically get out the drill, sandpaper, and Easy-off. I know it’s impossible to believe, but the rougher texture of new pans does NOT make it less non-stick. Really. It’s all about the seasoning, which is an ongoing process, not a one-time thing. If you’re obsessed with having a “glassy” smooth finish, use the pan! It will happen in time just like your grandmother’s. I’ve got a Lodge skillet that I’ve used for only 4-5 years, and it’s perfectly smooth just from daily use and care. I’ve never seasoned it. They did that for me at the factory. I just keep it up and it gets better and better. I guess some people are more concerned about the nostalgia of their skillets, but I cook in mine, so it seems a little silly to spend 12 hours on a skillet that’s already ready to go. Also, if you’re expecting to cook eggs with zero oil/butter, get a teflon or learn to poach.

  17. I left my Lodge simmering on the burner too long, the liquid evaporated and I burned off a good bit of the seasoning. Great article and some great nuggets of info in the comments too!!

    I had great results with the following procedure:

    1) stripped the residual seasoning in my self-cleaning oven.

    2) the lodge pan was bumpy because they use coarse foundry sand, so I sanded it a bit. I didn’t go too crazy, but it’s much smoother than when I bought it.

    3) rinsed it very well and then filled it with water and boiled for a half hour. Rinsed again with hot water and boiled water for half an hour again. I got some nice black rust on it.

    4) I rinsed it well and dried it in the oven per Sheryl’s original instructions. Then followed her procedure for 6 layers with organic Flaxseed oil.

    The pan is awesomesauce!! 😉 Thank you Sheryl!

    By the way, I was considering using Sardine oil which has a higher iodine value and also has a low smoke point. I found some next to the Flaxseed oil at Whole Foods, but unfortunately it wasn’t pure and had citrus flavoring and vitamin E. I did some searching for food grade pure Sardine oil but could only find pet grade oil (Icelandic Pure).

    How regulated is the pet food market? If we could be certain the product was pure it might make a good alternative for seasoning cast iron. I would accept the risk of rancidity since it’s going to be polymerized anyway.

    http://journeytoforever.org/biodiesel_yield.html

    http://www.cookingforengineers.com/article/50/Smoke-Points-of-Various-Fats

  18. what about hemp oil? Like flax oil it has a low smoke point and lots of omega 3, 6, and 9s. Would it work just as well as the flaxseed oil?

  19. Hi,

    According to a website affiliated with the Oxford University chemistry department, the flash point for linseed/flaxseed oil is 222 degrees Celsius – about 432 degrees Fahrenheit:

    http://msds.chem.ox.ac.uk/LI/linseed_oil.html

    (I’ve seen the same numbers given on other sites, as well.)

    The flash point for an oil is the point at which it can vaporize to form an ignitable mixture in air.

    So this might be a reason to keep the oven temp at 400F when seasoning pans. The point at which linseed/flaxseed oil will burn seems to be a lot lower than the temperature of a standard oven cleaning cycle (which I assume is designed to burn of fat that has higher smoke-/flashpoints than linseed/flaxseed oil does.

    (According to the same site, spontaneous ignition of linseed oil occurs at 343C/650F, so definitely stay well below that!)

    Thanks very much for these terrific instructions, Sheryl! I’m about to give them a try, but I’ll keep my oven temp to 400F after rubbing on the oil.

  20. Hey, I like your article! I’ve been struggling here, and having some understandable science on my side is a great help. I’ve done a few Internet searches, and you’re right – no one really says the same things.

    I’ve accumulated a couple cast iron skillets – two of which I got at a garage sale – along with a new Dutch oven. To put it bluntly, I barely know how to use them. I tried to reseason two of them, but the surface came out sticky in places and bone-dry in others. I used Crisco, and I suspect I put it on too thick. (Is that what happened?) I preheated it in the oven for a few minutes, then put the Crisco on, and stuck it back in the oven to let it bake for two hours, like one set of directions said. *shrugs* I did almost the exact same thing when I first got them, and it came out all right then. I really have no idea why this time was different.

    I also suspect that I managed to get rust on one or two. Maybe? Or maybe there already was rust on the old ones? Maybe that’s not an issue at all. I don’t know. I’ve tried a couple different cleaning methods for after each use, too, but again, no one ever gives the same directions. One said something about just using coarse salt, but that didn’t get it really clean. A few said it’s all right to just use water with no soap. (Definitely, definitely no soap. So I haven’t done that, at least.) *throws hands up* A few sources told me it’s good to reseason every once in awhile. Well, how often is that? About how long should a good seasoning last before another would be a good idea?

    As you can see, I need some help. Could you give a poor college student some extra tips? Or perhaps direct me to a good site or book or something?

    Thanks.

  21. I wiped canola pan on my cast iron pan last night, put it in an 250 oven for 2 hours. Let it cool in the oven overnight. Wiped out excess oil this morning. Put it in the cabinet. If I don’t use the pan often, will the oil become rancid? How will I know if it does? What should I do if it does?

  22. Thank you so much for the information… I grew up with cast iron and lament to the loss of so many of my grandmother and mother’s old Wagner and Griswold pans and skillets over the years. I am now trying to build up my own collection of beautifully seasoned cast iron… which may cost me a fortune 🙂

    My question is… after getting that beautiful coating, how do you care for it so you don’t have to re-season often???

    Thanks!!!!!!

  23. Great article, thanks! You should become an Amazon affiliate and post links to good Flaxseed oils on here. Because that’s exactly what I did, went to Amazon and bought some. Links on your post would simplify that process and make you money at the same time. Just my 2 cents.

  24. Hi, has anyone used this method for seasoning and then cooked eggs?
    I did and my eggs permanently bonded to the skillet more than the flax oil
    and yes I used oil when cooking them on medium heat
    Well, back to the way I seasoned before where the objective is not to make the skillet black and shiny, but to make it NON STICK!!!
    I have another pan that I seasoned myself from scratch and I cook scrambled eggs on it without ANY sticking
    Don’t use Cheryls method if you want your pan non stick
    her method is for hanging your pan on the wall and looking pretty

  25. Hi Sheryl, this post is awesome. I’ve been looking for some real advice on seasoning and this is the first time anyone has really talked about the science behind it all. Anyway, I have somewhat of a unique situation. I own a small crepery and we use cast iron crepe griddles imported from europe. I can’t put the whole griddle into the oven so I have to season it by heating up the griddle itself. They go up to 300 degrees celsius (about 570 fahrenheit). In the past I’ve tried canola oil, vegetable oil, lard, etc. but they all start to flake off after a month or so. Keep in mind that the griddles are in use for 12 hours a day, six days a week. So, I’m looking for a seasoning method that will last longer. Do you think this will work the same by using the heating mechanism of the griddles themselves as opposed to heating in the oven?

  26. hi sheryl,
    thanks for this. i just wondered if you know of an alternative method not using the oven? my pan has a wooden handle!

  27. So I went through the entire process, did it about 8 times. I had ruined the seasoning on my pan by leaving on the burner too long drying it, a few too many times. It started sticking really bad so I looked up reseasoning and found this page. Its a 12″ Lodge pan. I stripped it with oven cleaner, took 2x 24 hour soaks and lots of elbow grease with a stainless scrubber but I got it all the way down to bare metal. Then followed these directions, and have been using it for a while now. It works amazingly well. My old seasoning was great but took a long time to build up and get really non stick. This method, the first thing I cooked was frying some bacon wrapped dates. Even with oil in the pan, they all stuck immediately. However, after getting nice and crispy, they all released and that was the last thing to stick to my frying pan.

    I fried eggs and hash browns in it the following morning and it was perfect. Eggs slipped around with absolutely no sticking at all. Over easy eggs came out perfect. Hash browns didn’t stick at all, usually I would have them stick for the first few minutes until they started getting crispy, but not with this new seasoning.

    Ever since I’ve fried and cooked all sorts of things in it and it works great.

    My suggestion to those who failed, is to make SURE you follow the procedure very closely. I think the key things are VERY VERY thin layer of flax oil. Wipe it off each time until the paper towel is literally dry and wont pick any more up. Plus use high heat for long periods of time. I actually extended the baking time to about 90 minutes or so at 550. Repeated this 8 times and started using it. Before using it I did one last long bake with no oil on it, 2-3 hours at 500+ to really bake that stuff on there. Perfect, smooth, slippery seasoning. Rock hard, in fact it feels and reacts to a stainless spatula as if its just bare iron. Its great, and returned my favorite frying pan back to full functionality. Now I just have to not mess it up like I did before.

    Always have some oil in the pan when cooking something, and clean it up afterwords and it’ll just get better and better. I think it will work great long term as its only building up more and more at this point. The base that this article describes is a fine start and worked well for me. Thanks for the information!

  28. Do I coat the entire pan with flaxseed oil? The bottom, outer sides etc, or just the cooking surfaces?
    Soory if this has been covered.
    Thanks

    -Therron

  29. I learned that I can easily clean the grills on a gas stove top by placing them in a plastic bag, adding about 1/2 cup of amonia, tying the bag and letting it sit for an hour or two. Must be careful when adding the amonia and again when the bag is opened because amonia fumes are choking. After a good rinse in tap water, I can simply wipe off most of the burned on gunk. Light use of steel wool finishes the job. Only a little amonia does the trick because the fumes do the work. Do you know whether or not this would work for cleaning gunk off old cast iron pans? Thanks, Russ

  30. IRON PAN SEASONING FOR THE CHEAP AND LAZY???
    credit..organic lawncare for the cheap and lazy
    http://www.richsoil.com/lawn-care.jsp
    by Paul Wheaton who also has a cast iron article online:
    http://www.richsoil.com/cast-iron.jsp
    I am cheap lazy and seem on top of that seem have a shorter and shorter attention span.
    Just wanted to laud your perfectionism Sheryl! That popover job was more of a full restoration.
    Anyways I curse the guy who mentioned linseed/flaxseed oil the other night at dinner….CURSES! My house smells like some beatnik artist studio sans beatniks and minus art. Clearly with my ADD i did not read either the above article nor yours near attentively enough, just enough for inspiration to make a dangerous mess. I’ve been pretty good with my own pans , but not so anal as to not let others do the dishes, ya know. So here are some of my modified lazy man results. I worked with 4 pans, a huge skillet, with many scars because pizzas and other items have been cut in it over the years. a normal sized skillet, and a tiny newish one (saucepan) that came with a kinda rough finish. Only one did I “strip” this I call my “comal” (Spanish) it has nearly no rim, my favorite for fried eggs.
    A yi yi my ADD is kicking as well as the coffee, I’ll try and keep going here. I took shortcuts with all these, though was not so cheap and bought the fricking 20 dollar organic flaxssed oil, thats like 2 six packs of delicious hoppy beer…..wait thats not cheap either! Wah! Can I season pans with beer.
    I kept the existing base seasoning on 3 of them, I cleaned them first with salt and hot water (may have even boiled water to rinse) and a plastic scrubby ball thing (the brass ones are better) I heated them and did several coats in and on my 40’s O’keefe and Meritt. If any one scratches the chrome on this baby, I’ll hit them with the big skillet! I did my coats for much shorter time periods. I did a pretty good job of keeping the coats quite thin. Yes i got some “bumpys” but the long and the short of it worked good-enough. certainly the linseed-flax-seed adhered well to the year old bacon olive grape steak whatever I’d cooked on it seasoning, I found the minor “bumpys” come off on use or salt cleaning. Since the flax oil smelled like a stinky fresh mona lisa canvas, I used the veritable old BBQ seasoning trick, sliced an onion and cleaned it up while on the burner at high. a better seasoned seasoning, no?
    Two questions come to my lazy mind:
    Why not just season your pan by frying onions? Onion oil anyone?
    Why not just season your pan as you cook
    Is cooking with flaxseed oil as gross as I imagine? Is it a laxative? Yikes!
    guess thats 4 questions.
    Anyways I’m satisfied with my shortcut results for now. Time will tell. Anyhow if they allow you to pack your pans for the flight, please bring them on your next trip to California for comparison. I may just use the flaxseed for cleanups. PS I fried up some meat with the pan that I cleaned up with onion first and got no oile paint taste like I was afraid I would.
    MY BEST SHORTCUT: I only seasoned reseasoned the fry-pan’s cooking surfaces, I dont cook on the sides or bottom, these are not display items. Also, der, I did all my pans pretty much at once to save energy, etc.
    By the way the pitted huge one came out aok, yeah sure you can see the scars, but its non stick never the less. the one that was newer and has some texture to the bottom is stillsomewhat textured….I was thinking i might end up with a mirror like coating atop it, but is good enough.
    Now for the debacle of the “comal”
    I decided to go more by the book on this my favorite flat skillet. Looking back I’d go with electrolysis or just shelled out for a new one. This treasure of mine had lots of hard “gook” first started with mild abrasives like salt, didnt have my metal potscrubber, then used beer line cleaner: PBW…great stuff(should have let it sit overnight, (what me patient?). i tried to burn it off though i got no 900 degree self cleaning oven.I used steel wool(only had “0” too fine) Then being a dude, I had to use my powertools, you know. got my Dewalt lithium ion battery pact impact driver (yeah i know wish it was Makita) and a bit with a brass brush on it, THIS WORKED VERY WELL AND DID NOT SCAR/SCORE THE IRON. I sure as heck made a bug mess, I even used the stinky linseed oil on the pal while spinning the brass brush. Now this was not a vintage special heirloom pan. I will probably for here on out keep power tools by the sink. What a mess! black gunky spray everywhere, looks like some guy tried to change his crankcase oil over one of those spin-art toys! Good thing I’m a bachelor.
    I then followed your directions on this one but at shorter intervals as with the other pans, Still some irremovable charred chunks. This was not lazy of my, some might even say industrious! NOT WORTH IT,the ones with the existing base coat are as good if not better thus far.
    Shoot this junk-man has like four car batteries in his yard, I sure haven’t used electrolysis in some time, for that matter no laser hair removal or Brazilian waxing lately.I have just finished these 4 pans, havent cooked so much on them, will update.
    May fry some eggs up in thinner now. Always looking for the shortcut. Laziness is the mother of invention. I really appreciate your post, your methodical, scientific ways. Speaking of lazy, I will be shipping you my popover pans, whats the going rate for the works?
    In all seriousness, this seasoning could be a nice little side line for someone, like knife sharpening. I’m going to suggest it to the guys at our Santa Cruz farmers markets.
    Peace.

  31. Wyatt, that was hilarious, as much as I could follow it!!

    Cheryl, I just have to thank you for all your work and willingness to spend the time to share with others. Have tried other methods of seasoning that haven’t worked so well. I’m anxious to try this and will update when I do which may be sometime from now.

  32. My cast iron cookware has wooden handles; can these be safely seasoned in the oven?

    Thanks for your research; it is very helpful!

  33. Kudos to you Sheryl for the informative article.

    My question is this: I have a cast iron kettle that I want to sit on our wood fired stove, to act as a humidifier.

    I want to be able to season the interior so it does not rust.

    Would your method work for that application, do you think?

    Many thanks.

  34. Thanks for the information on seasoning cast iron.
    I wanted tp comment on the bumpy surface of some of the skillets sold today. I also got a Lodge skillet and wanted the surface smooth. I sanded it with an angle grinder with abrasive paper attachment. Perfectly smooth now! I know a lot of cooks don’t own one of these, but maybe they know someone who works with metal, or does auto body work – never hurts to ask.

  35. I have been pulling out my hair over this. My dutch oven and three pans have been stripped and reseasoned three times without results (after doing internet searches all over the place), and the one time I ventured to use my dutch oven (with brickets) I had a rusty mess. What a cleanup job that was! By the way, you can strip cast iron in a self-cleaning oven

  36. Is Lodge Cast Iron Skillet pre seasoned from the factory done with something that is safe to cook in? Or should I strip it and re-do with flaxseed oil?

    Thanks,
    Hugo.

  37. Thanks for the links. I wish canola oil was in the table with the iodine values. I’m pretty sure that’s higher than soy oil. I found a link with another table at one point, but I can’t find it again to save my life.

  38. Hugo, I’m not sure if Sheryl emailed you a reply. Personally, I’ll say you can go ahead and cook with the Lodge pan — the seasoning is okay, not great. Be sure to use oil when you cook, in order to reduce the likelihood of sticking. The more you cook with it, the better the seasoning will get. I’ve had a couple of Lodge pans that I stripped and re-seasoned, and the results were good; likewise, I’ve gone ahead and cooked with other Lodge pre-seasoned, and have also been satisfied with the results.

  39. Thank you for helping me fix my cast iron pans, they look fantastic now!! I am wondering though, since the reason I started using cast iron pans was because I was anemic and I had heard using them would help me get more iron, but now that my cast irons do not stick and are glossy and coated with the flax oil, will I still be getting any amount of iron from the pan into my food?

  40. Hi Sheryl, I just read your research on the flax seed oil coatings. It is very good information and I just seasoned a cast iron casserole pot with olive oil. My question is; since I just seasoned it with olive oil can I just go over it with a coat of flax seed or will this ruin it. Will it become toxic if I do this. You mentioned above you did six coats. Is two coats enough?

  41. Hi Sheryl,

    Thanks for your great posting on cast iron pan seasoning. I work in the nutrition kitchen at my university and we season with coconut oil. Do you think this is a good choice? I initially seasoned my pans at home with flax oil which created a thick very smooth coating like you described. Do I need to use the same oil each time to maintain the initial seasoning – meaning once I season with flax, always use flax? I tried using coconut oil when I ran out of flax at home, and it doesn’t seem to adhere to the thick dark layer that the flax seasoning created. Obviously we’re going to be cooking all sorts of fats in our pans and those will adhere and polymerize little by little, but when we clean the pan and apply a layer of fat, should that always be the same type of oil, or does it matter?

  42. What about Camelina Oil? I can actually find that, and it’s supposed to be very similar to flaxseed oil, but with a longer shelf life.

  43. Hi, I loved your article. I just bought a cast iron pan from Ikea. I would love to season it as you described but it has a wooden handle. So putting it in the oven is a no no. Do you know how I should go about seasoning it on the stovetop?

  44. One minor thing. Heating the pan will not open the pores. That’s not going to happen. As the iron heats, it will expand slightly. That will close the pores, if it does anything. I’m not convinced that the iron will expand enough to matter, but it’s a certainty that the openings won’t expand.

  45. Cheryl,
    I just finished re-seasoning a cast iron pan using the Flax Oil method. I followed the instructions to a tee. I was very proud how the pan looked but
    just finished cooking two eggs and they both stuck to the pan, it’s a mess.
    I used an Organic Flax Oil from Spectrum. Please let me know what may have went wrong.

    Jerry

  46. Hello, I’ve read your article and am very interested in trying this method to season my cast iron! I Do have a few questions though and hope this is still being checked. If using flax to make a solid coating, how do we make sure that those carcinogens that are produced when the oil is heated so high do not leach into food that is made later as in the same way they do with normal non-stick pans? thanks!

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