Using and Seasoning Cast Iron Pans
Making the Most of your Cast Iron Cookware
Reading Time: 15 minutes
By Paul Wheaton & Suzy Bean – Cooking with cast iron has many benefits. There are a few rules to follow however in order for your cookware to last. The first rule of thumb is seasoning cast iron cookware before using it for the first time. This creates a nice protective layer which not only protects it from rust but makes it much easier to use.
Cast Iron Cookware in a Nutshell
1. Use a good cast iron skillet with a glassy-smooth cooking surface (Griswold or Wagner). The new cast iron with the rough cooking surface is going to be frustrating (Lodge Logic).
2. Keep it dry! Using water short term (minutes, not hours) has its uses. When the time comes to put the cast iron cookware away, give it a few seconds on a hot stove, just to make sure all the water is out.
3. Use a little oil or grease.
4. A little smoke is a good thing.
5. Too much heat on an empty cast iron skillet can ruin the surface or even crack the skillet.
6. Clean cast iron immediately after each use, leaving a very thin layer of oil or grease.
7. Avoid soap! You can use soap on cast iron, but it is better if you didn’t.
8. Use a stainless steel spatula with a perfectly flat edge and rounded corners.
Cast Iron Cookware Details
Cooking with cast iron is one of those things where I failed utterly and repeatedly until I reached out to a few dozen people for help. I can now get that egg to slide off a cast iron skillet every time.
Why Use Cast Iron?
There are many things that drive me to use cast iron:
I’m convinced that “non-stick” surfaces, such as Teflon®, are toxic. Newer products come out that sound better, but I cannot help but think that folks just have not yet learned how toxic the new surfaces are. At the time of this writing, I feel comfortable cooking with cast iron, some steels, and glass. I avoid all chemically treated cooking surfaces, aluminum, and copper.
Cooking with cast iron also helps folks get more iron in their diet to build more red blood cells. Doctors recommend that those with anemia cook with cast iron.
Many of my happiest memories involving cooking, involved cast iron. I remember my grandad cooking almost everything we ate in a cast iron skillet. For a long time he was a professional mountain guide, and when he took me with him, the cast iron skillet would come too!
Cast iron can last hundreds of years. Many modern skillets/griddles last only a few months to a few years.
Start With a Good Piece of Cast Iron Cookware
I bought a brand spanking new “Lodge Logic” cast iron skillet at a department store. After seasoning it, and using lots of oil, food sometimes stuck to it and sometimes didn’t. I gave Google a big workout and I found lots of Internet forums to ask lots of questions. The most common feedback was to take a close look at the cooking surface of this new skillet. It’s rough. Apparently, there used to be two grades of a cast iron skillet one could purchase. The first is where molten iron is poured into a mold and that’s it. The second is where they take the first and machine out the cooking surface to make it much smoother.
Today’s new cast iron cookware is all the first kind. The surface is rough. I shopped around for a long time to try and find something new with a machined surface. The closest thing I found was a griddle made from sheet steel.
Many of the experienced cast iron folk recommended buying a heavily used skillet. The most popular brand being “Griswold”—a company that went out of business in the 1950s. Not only were these skillets machined, but if they were heavily used, their cooking surface would be downright glassy!
I bought a Griswold number 10 cast iron skillet for $20 plus shipping on eBay. This was a huge improvement over the Lodge cast iron skillet. I have to mention that I tried to buy a Griswold cast iron skillet for a friend a few months ago and the price was more like $50! But I easily found other old (Wagner) cast iron skillets for $15.
Time passed and I thought “Why not take the Lodge cast iron skillet with the rough surface and grind it down myself?” I bought a bunch of sandpaper designed for use with metal and figured 20 minutes with my different power sanders and some elbow grease should make it right as rain! Three hours later, I had burned through way too much sandpaper and the results were so-so. It was a messy, icky experience that left me numb and wobbly with a ringing in my ears for a few days. The skillet worked okay for a few weeks and then cracked.
I think a person could buy a new cast iron skillet, follow all of the advice on this page and if used twice a day for six months, it would probably be just as good as an old skillet. The most important ingredient would include the use of a stainless steel spatula with a flat edge: as it is used over and over, it will take the “peaks” off as the “valleys” fill with “seasoning”(more on the spatula and “seasoning cast iron” below). It’s just that the first few months will have more frustration than if you started off with a great cast iron skillet.
Seasoning Cast Iron
Seasoning cast iron is the act of creating a hard layer of petrified oil/grease on cast iron or steel. Maintaining a good cast iron seasoning is the most important aspect of keeping stuff from sticking to cast iron cookware. Each time you cook with oil/grease and don’t have to scrub the cookware afterward, you add another layer. Scrubbing, scratching, or soaking the cookware in water likely removes many layers. A well-seasoned cast iron skillet will have dozens of very thin, very hard layers — so many that it will appear to be black instead of the silvery gray of the raw cast iron.
I think the best way to season cast iron skillets is to use them. In the beginning, you might use a little more oil/grease than you would normally use —— just to make sure that you don’t have to scrub afterward. Once you have some seasoning layers built up, you can use less oil/grease. That’s it!
Most folks believe that seasoning cast iron means that you put some oil/grease on the cookware and bake it. If I wanted to season my pan this way, I would:
• Put on a thin coat of oil/grease all over the cast iron skillet. Inside and outside.
• Put foil under the skillet to catch any dripping oil.
• Turn my fan on, because this is gonna smoke!
• Bake at 400°F for 15 minutes.
• Wipe out as much grease as I can with a paper towel.
• Bake for another 45 minutes, then turn the oven off, leaving the door closed.
• After an hour or more, remove from oven.
The nice thing about the oven approach is that you get a layer of seasoning all over the cast iron skillet all at once.
I became a bit obsessed with understanding this stuff and this fella, Alan, helped me in a forum: “What you want is a layer of heavily polymerized fat which typically includes a fair bit of carbon black bound up with it.” So it is polymerized fat, which is hard and slick. The carbon is the black stuff. A couple of chemistry savvy friends explained to me that “polymerized” means that the substance re-arranged its molecules to be in a different state. In this case, slick liquid oil becomes slick, rock hard solid oil. Apparently, this is very similar to how paint works.
This is the beginning of my education. It turns out that there are an infinite number of kinds of seasoning layers. It depends on the type of oil, the quantity of oil, the temperature, the duration of the heat. Some have lots of carbon, some not so much. Some make a glassy layer and some make a “sticky” layer that turns squirmy slick when heated. Some stick to the cast iron skillet better than others.
The oil/grease will often go through a sticky phase before becoming a seasoning layer. If you have too much oil/grease, you might never get past the sticky phase! The moral of the story is that thin layers are best.
An interesting thing about seasoning: It is usually quite mottled, or spotty, or spider-web-ish.
Photo 1: I bought this little cast iron skillet brand spanking new. It was gray. I did not season it in an oven. All I did was start using it. And I took pictures. This first picture is after using it two or three times. You can see how some layers of oil are darker than others. And mottled.
Photo 2: A little more use. See how the seasoning coloring is starting to get darker overall.
After this it will have so many seasoning layers it will just look black.
Photo 3: Shows a close up so you can see how some layers are more mottled than others and some layers are blacker than others.
A while back, a blogger named Sheryl contacted me and appears to have embraced my stuff and taken it a bit further. Our discussion can be found in the forum at www.permies.com, under, “Cast iron: polymerizing oils and a better seasoning.”
Removing the Seasoning Layer From Cast Iron
There are three reasons I know of for why you might want to do this:
• Your cast iron skillet has crusty blobs on it. I suspect that this comes from not using the right kind of spatula.
• You have a brand new cast iron skillet from the factory. Modern cast iron skillets have a layer of something on it that the manufacturer has decided to label as “seasoning.” I suspect that the stuff on that cast iron skillet has a lot more to do with marketing, shipping and profit margins than what you or I would want to eat. I think you really want to get that stuff off.
• There is rust on the cast iron skillet. While I have read of many ways to do this, the technique I use is to toss the pan in the fire. I have a stove for wood heat. When the fire gets to the point of being just coals, I toss the cast iron skillet on the top. The next morning I fish it out. All of the crusty or rusty stuff is turned to ash. I brush the ash off with my hand, then dribble a little oil on it and wipe that all over the cast iron with a paper towel. Then I start using it.
Which Oil or Grease to Use on Cast Iron Cookware?
I think that any edible fat will probably work fine. Oil, lard, shortening, animal fat, butter, etc. I tried olive oil exclusively for a few months. If the cast iron skillet needed scrubbing, it seems that the scrubbing would take off some seasoning, which I didn’t like. Some people swear by shortening (like Crisco) for seasoning cast iron. But I’ve heard some scary things about shortening, so I avoid it myself. I have used “organic shortening” which is actually palm oil. I’ve researched it pretty thoroughly and I like it! I also tried grapeseed oil for a couple of months. Everything started to get a gummy residue on it. I have switched back to bacon squeezins, palm oil, and sunflower oil. I’m also looking around for organic lard (since I’m not raising pigs for meat right now).
Let’s Fry Some Eggs!
For most folks, this is the big test. When I first started seeking cast-iron wisdom on this topic, I found the gold mine to be forums. People offered tons of advice. I’m pretty sure that I currently use all of the advice I was ever given. At times I try to skip some of the advice only to discover that every little bit helps.
1) Cast iron skillet history.
• The more seasoning, the better!
• Oil/grease has been used regularly. I don’t use oil/grease for pancakes, but there is a tiny bit of oil in the pancake batter. I think it somehow comes out of the pancakes as they are cooked.
• No soap or scrubbing for the last several uses. Sometimes something happens and you need to scrub. And the next time you try to use it, it just doesn’t seem as slippery.
• Used recently (a few days without use and it starts to get kinda sticky).
2) Use oil/grease. It doesn’t have to be a lot. One teaspoon should be plenty. Try to spread it around evenly.
3) Preheat. Maybe about three minutes? I’ve found that medium, or a little lower than medium is the right temperature for almost everything. Somebody told me that if you flick a little water on the surface, that if the water dances, the cast iron skillet is ready! I usually wait until I see a little smoke.
4) Add spices before the eggs. If you are using a little salt and pepper, sprinkle that on the cooking surface before the eggs.
5) If you are raising chickens for eggs and seasoning cast iron was done correctly, you’re in for a real treat!
Cast Iron Clean Up
This is something that will be completely different from other pans. With other pans, you generally want to leave a sterile surface. While you can do that sort of thing with cast iron cookware, it is better if you don’t. Leaving a little oil and salt behind is a good thing. If you try to wipe the surface of cast iron cookware with a paper towel afterward, you might get a slight brown or black residue—that’s fine. That’s oil and browned oil on its way to becoming part of the cast iron seasoning.
Most of the time, everything slides right out and there is no cleanup. Sometimes, I’ll use a paper towel to mop up a bit of excess oil/grease and take out any leftover food bits. As long as the skillet looks clean with a thin film of oil on it, it’s ready to be put away!
The mission here is to try and get the yucky stuff out and leave as much of the seasoning on the skillet as possible. It is possible to scrub the seasoning off of the cast iron. So, try the gentler approaches first.
For any cast iron skillet I have cooked anything with, this is the complete list of things I have ever done to clean a skillet. The gentlest (best) approaches are at the top.
Do nothing: You have served the food and the cast iron skillet looks plenty clean. There is an oily/greasy residue which is great for seasoning cast iron! Try to shoot for this kind of clean up every time!
Wipe with a paper towel: Sometimes this is all that is needed. If this works, you’re all done!
A little salt: If there is just a little bit of something sticking, and a paper towel alone doesn’t do the trick, put a little salt on the little bit of sticky stuff. The salt usually gives just the right amount of abrasion to remove the sticky stuff without scratching the seasoning off of the cookware. If this works, you’re all done!
Boil water: Put a quarter inch of water in the cast iron skillet and boil the water in the skillet. About 80% of the time, whatever was stuck just lets go. You could use the flat edged stainless steel spatula for a little help—being careful to try and leave the seasoning on the cast iron. Pour out the water and then wipe out the skillet with a paper towel. Follow the instructions below for “Drying a clean, wet skillet.”
Scrub: First do the boiling water trick—complete with the spatula treatment. Drain the water. If there is still food stuck, use a plastic scrubby thing. I like the kind that is a green rectangle about a quarter of an inch thick. Using a metal scrubby thing is going to take the seasoning off of the skillet. I think that any kind of scrubbing is going to take off some seasoning—so the trick is to take off all the food bits and leave as much seasoning as possible. Follow the instructions below for “Drying a clean, wet skillet.”
Drying a Clean, Wet Cast Iron Skillet
If you ever use any water, make sure that you thoroughly dry out the skillet right away. Otherwise, you will get rust!
It is really important that you use heat to dry the skillet. A towel just isn’t going to get it dry enough.
I place the skillet on the stove and turn it to high. When the visible water is all gone, I turn the heat off.
Keep your full attention on the skillet while the heat is on! I’ve had people insist on helping me by cleaning my cast iron. I would mention drying by heat, and they would turn the heat on and get busy with something else. Suddenly the kitchen is full of smoke and the seasoning is all gone! This is also a great way to crack a skillet.
Always Leave a Thin Layer of Oil/Grease
There is moisture in the air that can rust your skillet. A thin layer of oil/grease will keep your skillet safe from this. Since most forms of cleanup leave some oil/grease all over the skillet, then you really don’t have to do anything here. What’s there is just fine. If you did some cleanup that leaves the skillet looking pretty dry—with no oil/grease layer, put a few drops of oil on the skillet and spread it around super-thin with a paper towel.
• Soak cast iron in water
• Wash cast iron in a dishwasher
• Leave cast iron outside
• Leave food in cast iron
Avoid using soap on cast iron cookware. About half of the people that use cast iron are sworn to never let soap touch it. This concern comes from folks that learned how to make soap in cast iron containers. All soap is made using lye, and the lye will destroy the seasoning layer. But making soap without lye is now being done, so soap and detergent used on cast iron will not harm the seasoning layer.
One could say that soap helps to remove bits of food smaller than you can see. I think there is some truth to that. Of course, the residual oil will help to preserve that food. And the future fry will kill anything funky that might have grown on that food. And the food is so small that it cannot be seen, so it really isn’t too much of a problem to begin with. I think this is a case where the upside (preserving the top layers of the pan) has more value than the downside (removing 0.001% more food).
The Right Kind of Spatula
This is sometimes called a “pancake flipper.”
It has to be metal. Some folks will get concerned that the metal will scratch the surface and ruin the skillet, and their thinking is spot on, but the wacky thing is that in this case, we want it to scratch the skillet. But not just any scratching. We want just the right kind of scratching. Because with just the right kind of scratching, the surface of the skillet will get better and better. Smoother and slicker. Flatter. Bumps of fused-on ick will be scraped off and any pits will be slowly filled in with seasoning.
As I travel and people show me their cast iron, I sometimes see a piece that has big black tumors on the cooking surface. And then I put on my Sherlock Holmes deer-stalker cap and deduce, “You use a plastic spatula, don’t you?” Gasp! “How did you know!” At some point, something stuck to the skillet. The plastic is not able to scrape it off. And then other little bits got stuck to the first bit. As time passed, this bump got bigger and bigger. If a metal spatula were used, the first little bit would not have been more than a few minutes old before it got scraped off. These skillets with the big tumors are going to have to have all the seasoning removed and started over.
The illustration at left is the super close-up of the cast iron skillet of my mind showing the original lumpiness of the raw cast iron, followed by layers of seasoning and the occasional bit of stuck on something-or-other. (See illustration on the previous page.) The idea in this picture is that a plastic spatula is used. So the surface is never scratched and lumps and stuff just do their lumpy thing.
Now we start with a similar cast iron surface and the only thing we change is that we use a stainless steel spatula with a flat edge. A scratchy edge. But just the right kind of scratchy. As time passes, the peaks of lumpy seasoning get scratched off and the cast iron pits get filled in with seasoning. The cooking surface gets smoother and smoother. Unlike Teflon, years of regular cast iron use makes for a better cooking surface.
So now you can see the value of avoiding plastic, or anything other than metal spatulas. Stainless steel is all that I use. I have seen some steel spatulas that rust. Yuck! I have seen spatulas that have some sort of chrome-ish covering—you really need to avoid that—that stuff flakes off into your food! Yuck again! Stick with solid stainless steel.
Now for a bit of focus on the shape. There is the edge of the spatula that will contact the surface of the skillet, and there are the corners of the spatula that will contact the edge of the skillet.
Spatula edge: Nearly all metal spatulas have a slightly rounded edge – those will scratch the surface of our cast iron in a bad way. The surface will end up uneven as the scratches accumulate over the years and seasoning cast iron won’t help. With a flat edge, the surface will become flatter.
Spatula corner: The rounded corners are important because the inside edges of the skillet are rounded. I have a spatula now that is good except that the corners used to be really sharp—not rounded. With years of use, they are starting to get rounded, so where did those little bits of stainless steel go? I musta eaten them! Hmmm… maybe I should take it out to the shop and grind the corners a little…. The point is that they still are not round enough. I finally found another spatula that came with rounded corners—I like that much better.
Wood handle: With a wood handle, you can rest your drippy spatula in the pan and the handle won’t melt or get hot.
Do you believe that seasoning cast iron in the oven is the best way to season it? Or you have another approach?
Originally published in the September/October 2011 issue of Countryside & Small Stock Journal.