cast iron 101

cast iron 101

Cast iron pans elicit as much fear as they do fervor. For every cook out there who swears by their cast iron skillet, there’s a cook out there who is petrified to use it. I asked a few of my friends and family what made them resist the siren call of cast iron and they all pointed to the same anxiety. They were afraid of its upkeep, which admittedly at first, can seem daunting. But with a few simple rules, you can maintain your cast iron indefinitely and even pass it on to your children or grandchildren. Personally, I’d be pretty excited to get one from either my mom or my grandmother, but I just learned, much to my horror, that their maintenance of it was incorrect (hence them having issues with it). And so, allow me to share a few tips with you about cooking in, caring for, maintaining, and reseasoning your cast iron skillets.

A properly seasoned cast iron will develop a non-stick like coating and will cook your food to perfection. That incredible heat retention and distribution will deliver magnificent results. There’s a reason that cast iron cookware has withstood the test of time. What could be simpler?

cast iron 101

1. Warm It Up, Chris*: When warming your cast iron, start with a low heat setting first and gradually increase. Don’t just place the pan on high heat, or place it in the hot oven (warm it inside the oven as it warms).

2. Cooking: When cooking in your cast iron, try not to cook foods with high acid content like tomatoes – it can damage the seasoning and also impart a metallic taste to your food. Stick to regular frying, sauteeing, and whatnot. If you want to bake with your cast iron, make sure it’s an older well-seasoned pan. New pans should be used only for frying to get more seasoned.

3. Don’t Be So Cold:After cooking, please don’t try to cool your pan by thrusting it in cold water – you can actually crack the pan that way.

cast iron 101

4. Washing: When washing your pan out – just use a stiff nylon pad or brush, never soap (as that strips the seasoning) and hot water. Wipe the pan dry. Some people choose to lightly coat the inside of theirs with a tiny bit of oil and heat to rub the oil in. Another good method, and one I use very often, is to dump a generous amount of kosher salt into the pan, and scrub with a washcloth you’re not sad to get greasy or a paper towel with a small amount of water. Rinse and dry immediately, preferably over a low flame.

5. Reseasoning: Sometimes the state of one’s cast iron pan gets to be quite dire. Not to worry – you can reseason it and it’ll be back to its great self in no time. What you want to do is to spread a thin coat of a neutral oil (like canola) on the inside and outside of the pan. However, the best oil to use is flaxseed oil. Flaxseed oil, much like linseed oil used in oil painting to achieve a hard, shiny, dry finish, is a “drying oil”, except it’s edible (unlike its oil painting cousin). The process that occurs when your oil dries to a hard, shiny and not sticky finish is called “fat polymerization”. So the best oil to use for fat polymerization is a drying oil and flaxseed oil is the only edible drying oil out there.

Line the bottom of the oven with some tin foil to catch any drips, and heat your pan, upside down at 400 degrees F. I usually place my rack in the top third of the oven. After an hour, remove from the oven and let cool. Check your pan – has it blackened, or are you still looking at a few grey spots? It’s possible your cast iron could use another reseasoning session or two. Don’t be afraid of multiple sessions – just remember: you can always get the pan back to a well-seasoned shape.

6. Sticky!:There’s sticky gunk in your pan – what do you do? If the gunk is on the bottom, I have found that it’s not so bad trying to remove it if you boil some water in the pan and then try to loosen the gunk with a stiff nylon brush. On sides, a heated pan makes it easier for the gunk to come off, just be careful and not burn yourself. Always wash your pan in hot water to prevent it from cracking. Also, hot water is more effective at dissolving any stubborn sticky spots. Actually, one of the reasons I don’t coat my pan in oil after cleaning is that for some reason, I find that it always gets sticky afterward. I much rather keep the pan dry and reseason as needed.

7. Rust: Your cast iron skillet is showing some rust. You can easily remove rust by scrubbing with equal parts of oil and salt on the rusty spots. If rust is too pervasive, you can try using fine steel wool. Once done, wash the skillet, and dry it thoroughly. Reseason according to instructions above.

cast iron 101

There, I hope this has helped to clear up any mystery/confusion about cast iron pans. And I hope that those of you on the fence, afraid to give it a go, now feel excited and confident that you can maintain your cast iron in great condition. A little bit of effort with cast iron – can be extremely rewarding. It will soon become your go-to pan – you’ll see! And if you have any questions on the heels of this post, leave a comment below and I’ll answer to the best of my ability!

*(I’m about to!)


  • sharon

    I want to give cast iron a try – my Mom never used them. What cooking instruments can you use? Is metal ok? And what about making a pan sauce? Can you use a whisk? Or does that damage the seasoning? Is any acid ok? Like a splash of lemon juice, wine, or sherry?

  • Radish

    Sharon – excellent questions, you can definitely use metal – I prefer wooden spoons, but metal whisks are perfect. I’ve used them with great success. I would not use anything acidic when cooking in cast iron. I’m going to check to see if I mentioned it, I thought I did. I’ve been okay using wine, but lemon juice has too much acid. Let me know if that helps.

  • Renee (Kudos Kitchen)

    Wonderful tips, some of which I had never heard before. Think I’ll have to haul out my old cast iron dutch oven very, very soon now. Thanks for all the wonderful information! I think I hear some fried chicken calling my name :)

  • Warner aka ntsc

    Do not drop cast iron on a ceramic tile floor, the tile will shatter and so may the cast iron.

    My wife did that with the most expensive piece we own.

    You can get most of the advantages of cast iron with few of the disadvantages, by using a ceramic coated cast iron. Simply mortgage the first born.

  • Abby

    These are great tips. I follow most of them already, but I am going to get some flaxseed oil for future seasoning. I also don’t season the outside of my pan but plan to start immediately. I have loved cooking in it since I finally took the plunge a few years ago.

  • Richard

    These are great tips. I would like add one more. Instead of washing it in the sink, pour a quarter cup of coarse salt and a few tablespoons of canola oil – or whatever cheap vegetable oil you have on hand – into it and scrub the inside with a cloth or paper towel. Oil-lubricated salt is a very effective cleanser, and it maintains your seasoning. I was very skeptical, but it totally works. I haven’t had to re-season my cast iron pan in years. The pan only really touches water for a brief rinse to get the last of the salt out. Throw out the rest or save it in a can for the next scrubbing. (Also, I wouldn’t use any amount of acidic ingredient in the frying pan, including tomatoes, lemon juice, or wine. Those recipes are for enameled cast iron.)

  • Radish

    Richard – thanks for the cleaning tip – very useful; I think I mention the acidic tip above.

  • Lydia

    With the salt-cleaning tip, you can also get away with using just a small amount (couple teaspoons) with a couple drops of oil to use as a scouring agent. I have a tendency NOT to wash my cast iron pans very often; since I use them mostly for frying eggs, pancakes, etc., I just heat the pan until the stuck-on bits char, scrape them off and wipe the pan out with a wet or dry rag.

    Another thing to remember about cooking with cast iron is that the iron reacts with oxalic acid, which is present is most dark leafy greens. This reaction tends to turn the greens a more putrid brownish-green color more readily and can make them even more bitter.

    Thanks for the flaxseed oil trick! I have some at home needing to be used up too!

  • karen stewart

    First, thank you for the heads up on flaxseed oil. We like using our cast iron pans, but have not heard about flaxseed oil before. My real question — Do you have any experience with really, really grimy cast iron pans? I’ve inherited a whole pile of different size skillets, corn bread pans, and dutch ovens that are really encrusted in . . . ??? Inside and out. Maybe used on an open fire? And then they were stored in a barn for years. I don’t know where to start to fix them!

  • Radish

    Karen – hmmm… let me do a little research – congrats on the inheritance – let’s figure out a way to make these usable for you!!

  • Julie @ Pary Moppins

    @Karen Stewart, As far as inheriting a set of cast itron, congrats! If it is nasty and looks like it has barnicles growing all over it, all you have to do is throw it in a fire. No seriously. If you are bbqing, lay it amongst the coals or if you are burning leaves, throw it down in the pile or if you have a fire going inside, then put it in the fireplace. The extreme heat will burn off all of the gunk and then you can start over with the scrubbing off of rust and carry on seasoning from there.
    A traditional wedding present around these parts is to get a cast iron skillet (corn bread pan) that someone has lovingly seasoned for you.
    One more benefit from cast iron cooking is that a little iron seeps into your food as it cooks – much preferable to aluminum…

  • Aubrey

    If the inherited cast iron is very encrusted you can soak it in a lye bath for a few days and it will be mostly clean. Then you can use electrolysis to remove anything that is still stuck on. It’s a bit of a process, but not bad if you really want to restore those pans. My husband has been doing it lately with some old Griswold and Wagner pans that we found on Ebay. You can buy the really crusty, dirty ones for a good price and then restore them and they are beautiful! These are much better quality than the newer, more common Lodge brand. They are as smooth as glass on the cooking surface. I LOVE cooking with them and I had never even used cast iron prior to 6 months ago. When seasoning the pan it is important to wipe off most of the oil prior to putting it in the oven to prevent it from beading up on the surface.

  • olya

    I didn’t have a chance to read through all the comments, but for cleaning sticky gunk I found peanut butter works wonders. I had some gunk that wouldn’t come off with any amount of hot or boiling water. Rubbing some peanut butter into those sticky spots and then rinsing out the pan worked like a charm. Unless you are allergic to peanuts, of course…

  • Carrie

    Great article and helpful comments, too. The only things I inherited when my grandmother passed away (there were 3 children, 10 grandchildren and 6 great-grandchildren by then) were her spatula, her potato masher and her cast iron skillet. That was 17 years ago and I have never once had to reseason it. I follow (not religiously) all of the afore-mentioned tips. I rarely ‘wash’ the pan – certainly never use soap. And I love that there’s a little extra iron and a little of my grandmother’s legacy in every meal I cook in it.

  • Sara

    This is a post to bookmark! I have never heard of flaxseed oil as the best oil to use for seasoning–very interesting! I also appreciate the instructions on how to remove rust–I had heard someone suggest barkeeper’s friend but never tried it, this sounds much easier. I like to towel dry my pans and then heat over low heat briefly to make sure they are completely dry.

  • Jen

    What about flaking? The season on my cast iron Dutch oven seems to have some spots that flake black crud off – how do I deal with that ?

  • Sofya @ Girls' Guide to Guns and Butter

    You know, I have 6 or 7 of these and I beat the heck out of them and I do too put them over high heat and wash then in soapy water if I cooked something like fish in them or if they are too greasy. I also have one for bacon because I don’t touch pork but my kids do and I was that one with soap then just dry it and it’s just fine (that one came pre-seasoned though, unlike some of my other pans). They are more hardy than that, I find. To season a pan, including one that shows signs of rust, I just wipe it dry with a towel and then coat with a thin layer of oil which I spread with a piece of paper towel. Never have any trouble, and no fear of cast iron either.

  • karen stewart

    Wow, thanks everyone for the comments on cleaning up my inherited mess! Julie — we frequently have a fire going in or out, so will throw the cast iron in and see what comes of that! If that doesn’t work, I’ll have to invest in some lye and try Aubrey’s plan — agree that the Griswold/Wagner pans are much better than the newer ones. And I won’t forget the peanut butter, Olya, for difficult spots. Sofya, thank you for posting your site — love the recipes and your little ones are adorable and agree about handsome men and guns!

  • Radish

    karen – I find that Whole Foods carries it. Natural food stores too. Trader Joe’s has it in their supplement aile.

  • David

    I have just come across some old cast iron. I have cured 3 times and nothing. I have one an old girlfriends grandmother gave me that she bought new in 1921. It has never been a wonderful. My first choice was to heat the “new” pans but I live in the south. I have a fire place but it has not worked for some years now. I am trying some oven clean to strip one down re-cure and see what comes of it . Do you have any suggestion? Is it better to cure pans inside and out?

  • Radish

    David – what condition are the pans in? Any rust? any food residue? The pan must first be clean of all those things. Then you need to reseason. Let me know how it goes. Feel free to email me a picture – hopefully I can help that way?

  • Beverly

    I was on a mission to reseason my pans since they came pre seasoned and were not really as stick-free as I anticipated. I baked them at 450 for an hour and let them cool in the oven, and when they came out, there was a fine layer of rust. I scrubbed them down with steel wool, dried them in the oven at 350, and rust again! What should I do? Salt and oil scrub? My poor hands can’t take any more steel wool!

  • VP

    I used CLR to remove the rust that built up on my cast iron pan. I did this before reading that CLR should not be used on cast iron as the acids in it will react with the metal. Now I don’t know what to do? Any suggestions? The rust came off just fine, but now I’m worried if it’s still safe to use the pan or reseason it? Does anyone know what’s the problem with the acids in CLR reacting with the metal? Is it just that the coating will come off or are there health concerns about cooking in it post-CLR exposure? Thanks!

  • Radish

    VP – it does appear that you cannot use your cast iron has been cleaned with CLR. That is unfortunate, but the upside is that a new cast iron is under $20 for many pans so getting a new one isn’t the end of the world. Sorry about your pan!

  • fran

    I think that oils high in essential fatty acids, such as flaxseed oil, should not be heated heated because heat can turn the healthy fats into harmful ones.

  • Radish

    fran – from the research i’ve done and the nutritionists i’ve spoken to, if you heat flax seed oil you destroy its nutritional properties, but you don’t exactly get anything harmful. let me know if you have different info.

  • Steven

    You mean “elicit”, not “illicit”. The later means illegal or sinful and is not a verb. Thanks for the tips. I didn’t know about the acid problem.

  • olga

    Steven – thank you SO much for the correction! Ugh, and I knew the difference too! So thank you – fixed now :)

  • olga

    James – actually, when flaxseed oil is heated for this time at a high temp, it hardens and dries – as I explain above, the process is called polymerization. Fran isn’t quite right. Polymerization happens because flaxseed oil is a “drying” oil and happens to be the only edible drying oil. Another drying oil is linseed oil, used to dry oil paintings. However, linseed oil is not edible and can’t be used in seasoning a cast iron skillet. As for heating flaxseed oil, I know from a nutritionist friend that heat destroys its nutritional properties, but doesn’t, actually, make the fats harmful to the diet. Either way, the oil dries on the pan and doesn’t pose a threat either way.

  • Tommy Ivers

    Watching Super Bowl yesterday, I put shrimp sauce in a small CI serving bowl and forgot all about 1/2 cup of lemon juice in the sauce. The seasoning in the bottom half of the bowl was gone after the sauce was gone! It wasn’t down to bare metal (I’d seasoned it 12 times with flaxseed oil) before using it, so I tried re-seasoning it and not stripping the rest of the seasoning off the bowl. Gave it 3 re-seasonings with flaxseed and it came out great and is now as black and semi-glossy as it was before watching the Super Bowl.

  • Tommy Ivers

    Guess not. Anyway, with 12 applications of seasoning, that’s why the sauce didn’t strip all the seasoning away and it wasn’t down to bare metal but you sure could see what the juice had done! You can’t go wrong with the flaxseed tho!!

  • Joan m.

    Seaoned my cast iron pan in oven. When I took iy out on the bottom of the pan were little round black spots. What did I do wrong?

  • olga

    Joan – can you email me a picture of it? could be polymerization from oil concentration – which isn’t necessarily a bad thing.

  • Narda

    I have also inherited some cast iron skillets. The handles are rusty – not enough to come off on your hand, just enough to color them. The inside bottoms are whiteish gray and you can see where utensils where used in them. My mother and grandma both dried them over the burner on the stove to keep them from rusting. One of the pans is a little 8″ Wagner and it has “seasonoing” instructions on the bottom. It says after scouring thoroughly to coat with oil and heat in a 300 oven for an hour. I’m not here to nitpick time or temperature, but I am wondering about scouring – in our house that meant SOS pads or wire brushes. Are these ok to use if I’m going to have to re-season anyway? Also, I recently moved and there is no gas. I have a flat top electric stove – is this type of heat safe to use with my cast iron?

  • olga

    Narda – I would avoid steel wool unless you need to take off a lot of rust. I would first try to use coarse kosher salt and Lodge pan brush (sold on here); also I think that you want to stick with higher temperature and, again, flaxseed oil works much better because of polymerization (flaxseed is a drying oil). Keep in mind that you may need to do this over and over. Up to half a dozen times and maybe even a few more. The best part is – you can get there. Just about ANY cast iron pan can be revived.

    To clean it, I would use lodge brush and hot water, or kosher salt and paper towel and hot water; NEVER soap. And finally, you can use electric, induction, gas, whatever. It will all work.

  • denise john

    I was always told that the crust that builds up on a cast iron pan makes the food more flavorful, have you heard this? I never try to scrape the outside because of this. I have an old skillet of my Mothers, she is almost 95 years old, and I have been treasuring this buildup.

  • olga

    denise – i have not. i have heard that you want the pan to get blacker and shinier with age, almost like a thick coating that’s not greasy… and that’s better for the pan, makes the food nonstick. In terms of any remnants of food, I was always taught to remove it.

  • Joanne

    Thank you for this post. I love my cast iron pans but one has a bit of rust on the outside. I didn’t grow up in a house that used them so I’ve been looking for info online about how to care for them. This is a great post and I’m going to try cleaning up the one over the weekend.

  • Cherry Bomb Kitchen - Cherry Blast Issue 1

    […] Cast iron 101 – how to care for your cast iron skillet I love my cast iron pan and this post is informative in the care of them. This weekend, I will be cleaning up a pan that has some rust on the outside. Since you’ve checked this page out, the rest of Sassy Radish is a good read as well. […]

  • denise john

    thank-you Olga for answering my comment about a black crusty buildup on the outside of my cast iron skillet, the inside is smooth and shiny with no food deposits. I was actually wondering how long it takes to build up that kind of crust on the outside of the cast iron, my others are fairly new and smooth all over. I was wondering if anyone else out there in cast iron land had ever heard of this, let me know guys!

  • olga

    Denise – my grandmother had this theory too, that the pan gets better after you don’t clean the outside. I see what you mean now. To the best of my knowledge and use and experience, that’s not actually true. I think what she probably learned from someone and misunderstood (bc that too can happen) is that you want to keep your pan well seasoned inside and out. So the same way you clean it on the inside, you clean it on the outside. Does that help?

  • Earl

    Once I originally commented I clicked the -Notify me when new
    comments are added-

    checkbox and now each time a comment is added I get 4 emails with the
    same comment.

    Is there any approach you may remove me

    from that service? Thanks!

  • Sandi Folsom

    I inherited a 10″ pot and the bottom has a round spot in the middle. Grandpaw had an electric stove.
    How can I make it flat??

  • olga

    Sandi – I don’t think I understand your question – there’s a round spot or a round indentation?

  • Serena

    i have a big old cast iron teapot. the outside honestly doesn’t look that bad however the inside is a different story. its flaking and quite rusty. how would i go about fixing this? i’m thinking its bad enough for steel wool :(

  • lisa

    I have a 6 gallon pot with 3 legs. It was used as a flower pot for decades. How to get such a large pot to working order. I have heard to put it in a large fire. Do I build the fire in it, put it upside down or sideways.

  • olga

    lisa – that i, unfortunately, don’t know. if it’s been used as a flower pot for decades, i don’t know the extent of the damage or how much work it might need to be restored. if anyone reading this might know, please pipe in!

  • Linda

    My husband uses Locktite Naval Jelly to remove rust from many of his tools. Sooo, when he saw rust developing on one of the cast iron skillets my mom gave me, he used the naval jelly on it (per the instructions), rinsed it and then scrubbed with a steel wool pad. It came out down to the actual silvery shiny metal and looks great. My question, (after reading the comment about CLR) can I still season this skillet (it’s like brand new!) and used to prepare food? OR, does the naval jelly cause some type of reaction that renders this skillet useless? Thanks for any insight on this.

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