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.
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.
I did both my Dutch oven and skillet again last night using cottonseed oil. I modified my procedure slightly based on the suggestions on this page. The main deviation is that I still used a succession of more quickly timed coats. For each coat I rubbed oil on with one paper towel and then rubbed it back off with another. I did about 5 or 6 coats and all but the last one were “quick” coats where I left the pans in the oven just long enough to get some good smoke off of them (probably more like 15 or 20m). Then, for the last coat, I left the pan in for the full hour and then shut off the oven and left it in for another hour.
The skillet was already shiny and black so that was just going along for the ride. The dutch oven, however, was a recovery job and so had been scoured with metal and washed. In the end, it looked like it had been sprayed with polyurethane so I was really happy about that. I fried some potatoes and peppers in it and it seemed to work well, too. I’ll try some eggs this morning for a real challenge.
Update: I was able to get the eggs to separate from both my pans but with some difficulty and I used a fair amount of oil to start with. Not a concern for the dutch oven really as I typically de-glaze anyway. I did a test run comparison against a new T-fal Signature pan and realized I was nowhere close. With the T-fal I was able to cook an egg BONE DRY and get it to separate and slide in the pan with almost no prodding after a mere 30s of cooking. (BTW, I’m not a teflon hater I just enjoy the technical challenges of cast iron). Anyway, at this point I was kind if dismayed but then I watched a video by Paul Wheaton that was most impressive (http://www.richsoil.com/cast-iron.jsp. So I decided I needed MORE plasticized oil for a more uniform finish. I actually did this second seasoning pass on the stove top by putting the pan over medium heat and maintaining a temperature on the surface of the pan that varied between 500d and 550d. I actually verified this with an infra-red (no touch) thermometer but you can probably get similar results just raising the heat slowly until you get good smoke. So, I simply wiped it with a light coat of cottonseed oil and let it smoke. Each time the pan started to look like it was drying up I’d simply wipe it again right there on the heat. After about 15 to 20 passes I simply let the pan go until it quit smoking altogether. I then removed it from the heat and let it cool down to around 200d before wiping it with a light coat of oil.
To test my new seasoning technique I heated the pan to around 325d and cracked an egg into it. There was no added oil, salt, or pepper. I went simply with the light coat I had wiped on with a paper towel at the end of the seasoning. I was indeed able to get the egg to seperate from the pan with a small amount of spatula prodding and, once free, it slid easily in the pan. Given that the test was even more challenging than that in the video I am really thrilled. I’m curious to see how it holds up over use but that will take time of course. Hope this helps.
I read about you in Cooks Illustrated. Just baking my fry pans for the final time. They are looking good. I will be trying one out tomorrow when I will be frying some AAA striploin. In the past I have tried lard or what ever the old books would tell me. etc Looking forward to the test.
If you own a Lodge pan, don’t chuck it for new smooth bottom pan. I didn’t like the ruff surface in mine so I got out my drill and a sanding disk then spent about an half hour sanding the inside smooth. Seasoned with mixed results until I finally found a method that worked. Because of the stuff I cook in the pan, it required re-seasoning occasionally. Next time will be by your method. Thanks for the great site and instructions.
Interesting page, the first time I read about this style of seasoning was on chowhound thread:
http://chowhound.chow.com/topics/433869#2875040
Quite similar to your method actually with some different elements. Both of you recommend high heat (so the oil shoots past the tar stage into the polymerized and plasticized surface). I love the science presented here. You advocate the high heat for one hour and two hours of cooling for approximately six stages. She advocates cooking it all the way through, but that’s a lot of heat and a lot of gas.
Finally, she does recommend after it is all said and done to go ahead and cook it for another 3-4 hours I guess to really bake in the seasoning.
I think I’m going to combine the elements I like most from both and give it a shot.
What a cool experiment! After having found your technique in Cook’s Illustrated (they should comp you a subscr!), I’m halfway through the process with 3 lodge pans with seasoning removed.
Neither you nor ATK make clear if the repeating cycles include heating to 200 for 10 min each time prior to oiling (one comment response from you suggests yes). I’ve been doing so, but it means considerable delay for oven cool down. Now you probably (and surely ATK) have double ovens, but a single oven raises the question directly.
I understand the initial heating opens the pores, however, in later coats, the pores should already be sealed, right? So my inclination going forward is to skip this for the later coats. What process exactly did you follow? Could you update the post to be more explicit as to what needs to be repeated?
Secondly, if preheat is necessary, how important is the cold oven? Do you use a cold oven to control ‘total time spent in oven’, as in it takes about x min to heat to max from cold + 1 hr + 2 hrs baking in slow-cooling oven? Or does this stand in for ‘let the pans become cold before placing in cold oven’?
Thanks for your patience with questions & comments. I bet that while you’re stoked by the interest, the handholding can get lame. Great post!
Ah, 1 more q: do you think heating the pans stovetop at med low for 10 or so minutes could replace the oven heating? Since the point is just to get them hot to touch, perhaps this (step 1 from almost every classic seasoning approach I’ve seen) could help streamline for us with just 1 oven?
Well I finally bought a bottle of filtered flax oil and seasoned on top of my Crisco seasoned cast iron.
All I can say is wow! What a superior finish! I have only made one new coat of it and it really makes a difference. It is not as glassy looking as oil or Crisco. More of a dull matte gloss (better looking). I fried up some bacon and beef and there was no stick.
While it is seasonong, there is less stink and smoke too. I also found out how wonderful the tast of flax oil is also. I would season with flax oil even if the price tripled!
If in the event I have any problems of initial seasoning flaking off, I will just strip and redo with the flax.
Thanks Sheryl for the great information!
I too would like clarification of whether to repeat the heating to 200 degrees each time. Do you reheat to 200 to apply each subsequent layer or just skip that apply the oil and back into 500 degrees?
Thanks for the info and the time you took to figure this out! I stripped down a lodge skillet and I used GNC Natural Brand Flax Seed Oil. I was under the impression that this was pure Flax seed oil but now, after my fourth coat with it, I actually read the bottle and its not. Below are the ingredients; should I start over with a different more pure brand? Certified organic flax seed oil, organic rosemary extract, mixed tocopherols ( vitamin e), ascorbyl palmitate ( vitamin c), citric acid to protect freshness.. The last one is what Im most worried about.. oh, it also says contains soybeans but they are not listed in the ingredients..Any advice would be greatly appriciated!
Thanks so much for taking the time to document all this information. It’s been a huge help. Like you mentioned, the internet is full of conflicting information on cast iron, but your page stands out as a thoughtful and detailed write-up.
My fiancée’s mother gave me a few cast iron skillets this year. I’ve used your advice, and I’m halfway through seasoning the brand-new ones. I used a drill with a sanding disc to knock down some of the rough spots. They’re still not as smooth as vintage cast iron, but I think they’ll be quite nice when finished.
She also gave me a beautiful old Griswold skillet, which I’m in the process of stripping with oven cleaner.
Thanks again for the info. Can’t wait to try out this new cookware!
~MS
So glad to have found this through the mention in Cook’s Illustrated!
As for using lye to clean cookware: not to worry. It is highly soluble in water (especially hot water) and will rinse right off. Even if you ingest a teensy bit, it’s only sodium and hydrogen and oxygen (though it will no doubt taste pretty bad). Don’t put it on aluminum, though. Drano is actually lye mixed with pellets of aluminum. When you get it wet, the chemical reaction generates lots of heat that helps to melt and break down the gunk in your drain.
Sheryl: On May 27, 2010 you wrote “You can’t safely use sunflower oil in cooking.” Can you justify this statement? Refined sunflower oil has a smoke point of 246°C, higher than Peanut, Corn, Canola/Rapeseed, Soy, Olive, etc, and is very commonly marketed for as a healthy polyunsaturated oil for general purpose cooking use (including frying). In the UK, for example, it is one of the most common cooking oils. Since I moved to the USA I’ve been surprised at how hard it is to find, and generally disappointed with the flavour of the alternatives (none of them as “clean” a taste, in my opinion), where Safflower seems to come the closest.
Sheryl: on the post for cleaning the cast iron you mention washing soda – what is this? Also, do I still use the avocado oil or just start right in with the flaxseed oil? I am getting ready to start the process of stripping but want to clean the pans correctly after the vinegar/water solution.
Sheryl, I have a couple of pieces I have inherited. I am fixing to strip the griddle just a test run before I do my skillet so not to mess everything up. My question is..when I strip any of the pieces I have should it get rid of the corrosion on the bottom of the pan ? The griddle just looks porous..but the skillet looks bad to me. The bottom is thick in some places and smooth in others. It is so bad the skillet does not sit even on my ceramic stove top. But as I read I wonder if it hasn’t been warped?My husband keeps telling me to “put it in a fire” I know not to do that..but even if you could …why would some start a fire for a pan? Anyway…how should the bottom of any cast iron piece look? And why is it that the Griswold brand is known to be so much better? I am just learning and I don’t see a name on the bottom my pieces..there is a “G” on the back side of the handle of the griddle but not the skillet
Thank You, Stephanie
Sheryl, you are beyond genius! Thanks so much for your indepth instructions … excellent resource! I appreciate the time you took to post about cast iron. I look forward to trying your recipes, too! 😉
I have used & loved cast iron for years. I have a couple of questions for you:
(1) I thought I could store a few pieces in my garage when I moved & they rusted. Argh! What is the best way to clean them … do I just use diluted vinegar to get rid of the rust & re-season or start all over (strip each piece down to iron & follow your 6-7 phase process)?
(2) I read that rust can be cleaned from cast iron with a raw potato & baking soda. Have you tried this before? What are your thoughts?
(3) I know your first choice for seasoning is flaxseed oil. Is coconut oil okay to use, too?
(4) I have a reversible stove top griddle/grill (Lodge pre-seasoned). I think I remember you saying you have a stovetop grill. I know it’s best to clean it right after using it while it’s still warm so items don’t bake on. But, the grill side is still a bear to clean. Last time I got frustrated & used a grill brush (you know the one with the brass/metal bristles) with kosher salt to get into the grooves. Any suggestions or advice?
Thanks in advance for any answers you may have!
I just tried this and the results are good, but I must not have wiped all the opaper towel off the pan and now have little ‘threads’ baked into the pan’s surface. Any way to remove these? Next time I will do with a linen cloth. Thanks!
I hope this isn’t a dumb question but…
When seasoning, should we be rubbing the oil on all surfaces of the skillet (i.e. sides, handle, and underneath – as opposed to just the cooking surface required for non-stick)?
I would think the whole pan needs to be done in order to prevent rusting.
Now, if we do season the bottom side, what happens to this surface when direct cooking flame is applied?
Thanks
2nd question:
In a previous posting where you used (I think it was) avocado oil instead of flaxseed, you finished up with lard for a couple cycles at the end. Would you still do this with the flax oil coating?
Thanks
Thank you for a great post and thank you all for the great comments. Sheryl, I followed your directions to a tee — stripped some old griswolds with oven cleaner, sanded the remaining tough patches, and then went through the lengthy process of seasoning. All looked good until I washed them the first time with water and a scrubby sponge. Most of the seasoning came off, leaving the original iron exposed again. Also, although I seasoned the bottoms as well, when I wipe those down iron dust comes off. Weird, huh. Do you have any ideas? I’m at a loss.
Hello Sheryl
Thank you for the post. Interesting. I want to know if I can use sunflower oil or refined oil for this seasoning or if there is any other commercial name or substitute for flax oil.
Thanks
One tip to those of use with lower quality cast iron (the ones that start out quite bumpy and coarse from poor casting) is to hand polish the iron with silcon oxid paper (200 grit to 400 grit to 800 grit) and then season the pan as per Sheryl’s method. Make sure to clean the pan well after polishing to remove metal shavings. This takes a little work but is worth it if you want a smooth finish.
Just wanted to say Thanks for your help Sheryl. I search for a few hours before finding your site,I used the electrolosis method from your link to clean five skillets a muffin pan and two dutch ovens we have then curred them using your method seven times on each one at 525 for one hour(an oven full each time).What a great method of curing castiron fantastic results truly nonstick Thanks again for sharing your knowledge Philip.
Hi, i have used the technique before but i’m just worried about the fumes coming out of my oven. Aren’t they carcenogenic also? It fills my whole room after baking the pan, i cant breathe in there.
Hi
Can you tel me about the production technolugy of cast Iron pot and pans?
Regards Ashori
Telefax?0098 21 44083292
Hi
Can you please let me know the cast Iron pot is prouce in sand mould or die cast?
Best Regards
M.Ashori
Telefax:0098 21 44083292
“I should add: there is now some safflower oil in the market that’s been modified to not dry.”
That would be high-oleic safflower oil. Any oil named “high-oleic” will be high in oleic acid, a monounsaturated fat, and is not what you want for this purpose.
Safflower oil (non-high oleic) has roughly the same PUFA content (75%) as flaxseed oil (72%), and is substantially cheaper. I’m not sure the n-3 vs. n-6 content matters much when you’re polymerizing them anyway.
Evening primrose oil and hempseed oil are slightly higher in PUFA, but are likely to be just as expensive as flaxseed oil. If you’re stuck in the boonies and can’t find safflower oil, corn and soybean oil are almost as high in PUFA (57-59%).
Thanks for the great information, Sheryl! I never knew what ‘seasoning’ actually meant chemistry-wise.
J. Stanton
http://www.gnolls.org
Is there any oil you would recommend cooking with (over others) after the pan has been seasoned?
thank you cheryl
after reading your post, i did some research of my own on polymerization. It appears that a lot of lab experiments saw significantly increased polymerization as measured by viscosity when kept at >450F for 3 or more hours and drying times for linseed oil of around 7 hours (i assume meaning fully polymerized). Have you tried longer bakes? I will try this method on carbon steel as it appears that no one has posted about it.
sudz
Found you through Cook’s Illustrated 🙂
I have a question. I recently purchased a Lodge Skillet (new so it is pre-seasoned). Would it behoove me to strip it and go the flaxseed way or just stick with the pre-seasoning? I also have a Lodge griddle (or comal as we in Texas call it)that is about 15 years old and needs a re-seasoning but has no crud on it. Should I just go for the vinegar/water bath and skip the oven cleaner portion before seasoning with flaxseed oil? Any advice would be most appreciated.
Shari:
I like refined, cold-pressed coconut oil because it’s neutral, extremely heat-stable, and nearly impossible to burn. The unrefined stuff makes everything taste like coconuts…but I still get cold-pressed, because the cheapo RBD industrial oil is sometimes hydrogenated.
Beef tallow is delicious for things that want a bit of beefy flavor. It’s why McDonald’s french fries used to taste so much better than they do now.
I don’t like to use anything that’s liquid at room temperature for frying because the polyunsaturates get all oxidized and glycated. Varnish is for furniture and cast-iron pans, not your arteries.
JS
http://www.gnolls.org
Sheryl, when we first got our new ‘pre-seasoned’ huge cast iron skillet, I got at it with our orbital sander and spent about 2-3 hours sanding it with progressively finer
sandpaper. Amazing results – especially now that I have re-seasoned them using your flaxseed method. Thanks.
OK I have seasoned an old #12 Griswold and an old #6 Wagner with flax oil and the results were absolutely supendous. I’m super impressed. But two questions have popped up along the way. First, flax oil is not cheap and since it goes rancid at the drop of the hat and even in the fridge has an extremely limited shelf life I was wondering what the “next best”, and cheaper oil would be? I ask because as a hobby I snatch up old skillets in need of care, clean them with electrolysis, and give them to friends and relatives. If there is an oil that is *almost* as good as flax oil I’d like to know what it is.
Second, what is the benefit of leaving the pans in the oven with the door closed to cool down for two hours? Needless to say that dramatically extends the time it takes to do do 6+ coats. What is the harm in either leaving the door open or pulling the pan and leaving it on top of the stove to cool? Isn’t the polymerization fully completed after an hour of baking?
Thanks in advance.
Hello from Jerusalem,
Wow, Sheryl! What a fantastic post, and a great help to semi-science junkies who are obsessed with getting things done right. I’ll be utilizing your method within a few days on some of my cast-iron cookware. It’s contributions like this that make the internet a great place. As far as aesthetics go, your pan looks terrific.
Big thanks and shalom aleyhem,
Gabriel
I had the same issue as Mike. When I used the seasoned pan – seasoned following your protocol – during cleanup the paper towels all turned super black.
Do the six coats need to happen consecutively, all in one day?
OR
Can I do the six coats over the course of six days/nights?
On researching flaxseed oils & linseed oils I discovered the reason you do not want to use commercial linseed oils such as ones sold in paint and hardware stores. If they are labbeled ‘boiled’ they have solvents and other substances added that will not only make you sick but might even kill you! Great comments…I learned a lot…thanks
i used organic linseed oil and followed your instructions applying a super thin layer, but instead of putting it in the oven, i heated it over the stove instead. It was smoking badly for the first 2 rounds very badly and left the kitchen towel black when it cleaned it off(after letting it cool till it was warm enough to handle of course!) and then followed your instructions about applying n heating and cleaning off etc… from the 3rd coat onwards, it smoked a little only and it leaves a beautiful dark brownish patina. I heated the pan from the base then left it on the stove in four other positions too. The pan has a beautiful hard smooth coating now (after 8coats) and i cant wait to test it out later cooking dinner!
I just purchased a new Griswold cast iron small square egg skillet. As it has never been used since its fabrication I don’t know whether new Griswold cast iron needs to be seasoned or is it preseasoned: This is the link to it
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&_trksid=p4340.l2557&rt=nc&nma=true&_rdc=1&item=300529126521&ru=http://shop.ebay.com:80/%3F_from%3DR40%26_trksid%3Dp5197.m570.l1313%26_nkw%3D300529126521%26_sacat%3DSee-All-Categories%26_fvi%3D1&si=I2ph9hiD%252FwTraSwYU2QLJUfWEBc%253D&viewitem=#ht_500wt_1156
Please, let me know whether the fact that it is gray in nature tells that it is unseasoned
Thank you so much, Sheryl. This information is invaluable. I’ve never been happier with my cast iron.
Uwe:
I’m pretty sure the black that comes off on the paper towel when coating the pan with oil after cleaning it is carbon, which is exactly what you want. My bet is the more the pan is seasoned, the less the carbon comes off.
I have used the oven cleaner (about 5 applications) on a cast iron skillet and there still is a small amount of black on the bottom of the skillet. Around the sides the black rust still remains but there are some places where the oven cleaner cut through the black rust. My question is: Should I try to get all of the black rust off of the sides or can I just season over it. The bottom of the skillet was where the problem was with rust where people had used scouring pads and even put it in the dishwasher. This pan was at our beach house. Thanks.
I also have a question. You mention that you should oil and bake the pan 6 times before it is finally ready for use. Do you have to do this in one complete session or can there be days or even weeks between oiling/baking sessions? As a working mother I don’t always have a lot of time to spend on seasoning a cast iron pot using the method you descibed here.
It was with great trepidation that I sprayed oven cleaner on my favorite pan. However, after the third flax application it became clear that this process was the real deal. Five treatments and now I don’t think I could get anything to stick if I tried. Now I’m lining up the rest of my collection to repeat the process.
Sheryl,
Thank you for sharing your research! I’ll be re-seasoning my wife’s skillets soon.
A question: I have a new kamodo style grill, & was wondering if you think your seasoning recipe would be beneficial on my grill’s cast iron grate? There will be times when the .grill/grate temps will be in 700 degree range,(steak searing). So my question is will the flaxseed seasoning withstand those temps, or would I be better off using the (good-ole-boy) method of slathering the grate with Crisco?
Thanks again for your article!
Philip
Not looking for an answer. Just sharing my experience. I followed the instructions per cooksillustrated which was essentially a summary of this website. After 7 applications, I tried to fry an egg, I used plenty of oil, and it stuck to the pan and when I washed the pan, with a nylon brush, no soap, the season came off. Will try again and see if I have better results.
Grape-seed oil, with an Iodine value of 135 and 64-76% linoleic acide composition, would seem to be a good candidate for cast iron cookware seasoning using Cheryl’s method. Does anyone have any experience using it for seasoning cast iron cookware?
Matt & uwe, Mike back here. A followup from my post from 12/27/10. I’ve now been able to season a pan and clean it without removing the seasoning!
I tried several methods to clean, and none of them did the three things I wanted: 1) cleaned the pan 2) left the seasoning intact 3) didn’t take an inordinate amount of time. The Alton Brown method of rubbing coarse salt in a bit of warm oil works eventually but takes a LOT of time on darker burned areas, and makes a salty mess. Simmering water and rubbing with a paper towel burned my fingers and removed some seasoning. Water and a soft bristled brush removed the seasoning (I’m guessing the bristles are more abrasive at the tip than we realize).
Finally I hit upon a method that leaves the pan looking better after each use! I’m modestly calling it Mike’s Cast iron Cleaning (MCC). The only equipment required is a plastic scrubbie, which is made of nylon that is twisted all over itself into a disk or ball. Be sure it doesn’t have any built-in soap or metal; you want a simple bunch of balled-up nylon.
In the MCC method you start with a skillet nicely seasoned by carefully following the instructions Sheryl gives. Now use it for cooking, being sure to put enough oil in the skillet (enough to coat plus about 1 teaspoon). After you’re done cooking, put oil in the hot pan if it is dry and then enjoy your meal. After dinner, conversation, and hopefully a glass or two of wine, the pan is cool enough to clean.
Turn the sink water to the hottest position (mine comes out at about 135F); I put on kitchen gloves so I don’t burn myself. Put the skillet at an angle under the water and you can see the most of the fat melt from the hot water and come right out of the pan. When the running water has cleaned all its going to clean comes the magic part of the MCC method. Leave about 1/4″ of water in the skillet and put it up on your counter. Now simply rub the scrubbie in large circles inside the skillet. All the crud comes up, and it actually seems to smooth the pan surface. You can actually see the waterproof seasoning emerge under the water as you swirl the scrubbie!
To finish up, as after any cleaning method you rinse, dry lightly with a towel, place on a burner or in your warm stove to make sure all water is gone, then rub maybe 1/4 teaspoon of oil over the skillet for extra protection.
hey Sheryl, great article very in depth. i have a question… i have two de Buyer mineral iron frying pans. i have been trying to season them for months with limited success. when i seem to get a good seasoning built up it eventually just sort of cracks in an area and flakes away. after reading your article i am convinced that it is largely due to the low quality vegetable oil that i’ve been seasoning with. do you think you’re technique would work on my pans as they are not cast iron. they are 99% pure iron. here is the link NOT to promote just for reference.
http://www.debuyer.com/product.php?id=711&cat=60&background=bleu1&lang=ENG
thanks for your time,
jordan
Hi Cheryl,
Thanks so much for this post. I followed your instructions and now have two beautifully seasoned cast iron pieces. I realize that one of them (5qt dutch oven) is of somewhat crappy quality (very rough along the inside walls) which likely led to it’s previously crappy seasoning. The flax seed oil finish is a significant improvement. The other piece (10″ skillet) is beautiful. So I now have my other pieces in the oven ‘cleaning’ to get the old finish off.
Again…many thanks for the detailed information.
Greg
Hi Sheryl,
I just read the Cook’s Illustrated article about seasoning using your method and came right to your site. I have an old Wagner frying pan that I picked up at the Salvation Army today. The black coating is coming off the outside of the pan, and there is some rust in and outside it. After I remove the rust, I intend to strip the interior and exterior and then season both with your flaxseed oil process. Is it Okay to do the interior AND the exterior? I thought if this works out well, I will strip my new Lodge frying pan and get the same super slick surface that amazed Cooks test kitchen.
Also, after this seasoning is in place, can I use safflower oil to cook with and continue maintaining the seasoning?
Thanks in advance for your time and trouble.
Kate