What is seasoning? The “seasoning” of cast iron pans that we’re so familiar with is scientifically called polymerization. This occurs when oils or fats in cast iron are heated high enough to change from a liquid into a slick, hardened surface that is molecularly bonded to the iron. It is what prevents corrosion and rust. You see, cast iron isn’t perfectly smooth. A microscope would reveal that it is actually quite pitted. As layers of seasoning build up, the surface becomes smooth and glass-like, and virtually non-stick.
How to Season Cast Iron
The conventional method. Vegetable oil and shortening are generally recommended for seasoning cast iron. A neutral oil with a high smoke point will yield best results. For this reason you don’t want something like olive oil. For those who avoid soy products, like vegetable oil and shortening, bacon grease is an option.
Place a cookie sheet covered with foil to catch drips on the lower rack of the oven and preheat. Lightly oil the skillet, including the handle, sides, and bottom. Invert the pan on the middle rack of the preheated oven. (Inverting the pan prevents the oil from pooling in low spots.) Bake at 350-450°F upside down on a cookie sheet for 60 minutes. Turn the oven off and let the pan cool in the oven.
Most sources, even Lodge, suggest doing this just once. But as Lodge shares and experience shows, seasoning builds up in layers. The more times you season the pan, the more layers you have, the more non-stick it is from the beginning. I was taught to do it three times. It’s just giving yourself a better start.
If your pan is sticky or gummy after seasoning, it’s because too much oil was applied. To remedy, just pop the pan back into the oven and bake until the stickiness is gone.
That’s how most everyone does it. And it works well. It’s what people have been doing for centuries. However, there is a better way.
The Ultimate Seasoning for Cast Iron
That new and improved method involves using flax seed oil. It’s a bit more expensive, but you may find it worthwhile. If you happen upon some discounted flax seed oil, it’s definitely worth it.
Flax seed oil is better than vegetable oil because it has six times the omega-3 fatty acids. During prolonged exposure to high heat, these fatty acids form a stronger matrix that polymerizes better to the pan’s surface. Here is the process used by the folks at Cook’s Illustrated:
Warm an unseasoned pan for 15 minutes in a 200°F oven. This opens the pores to allow the oil to penetrate better.
Remove the pan from the oven. Pour 1 tablespoon of flax seed oil in the pan, and use tongs and a paper towel to spread it around. Use a fresh paper towel to remove the excess oil.
Invert the oiled pan in the cold oven and then set the oven to its maximum baking temperature. Once this temperature is reached, heat the pan for one hour. Turn off the oven and let the pan cool in the oven for 2 hours.
Repeat this process five more times.
Results of experiments conducted at Cook’s Illustrated showed that this seasoning was virtually indestructible. It even withstood being run through the dishwasher. (I’m taking their word on that. However, I’m definitely not willing to risk running mine through the dishwasher. I’d have to repeat the seasoning process, and I don’t really want to do that.)
Now, you notice that the pan was seasoned six times. Couldn’t you just use a different oil and season the pan six times? After all, that would be six layers, and of course it would be better protected than just a single layer as is usually recommended. However, flax seed oil has a much higher smoke point, and that high level of omega-3s creates a much stronger bond at higher temperatures than other oils tolerate.
To maintain your cast iron pans:
Pour about a ½ teaspoon of oil into the pan. Use a paper towel to wipe it around and remove any food bits. Presto! It’s clean and oiled and ready to use again. To maintain that non-stick surface, use very little detergent, if any, to wash. Definitely nothing abrasive. Dry thoroughly to avoid rusting. Apply a light coat of oil.
Links to related posts:
Cleaning Dutch Ovens and Other Cast Iron Cookware
Do Cast Iron Pans Boost Iron Intake?
References:
https://www.lodgecastiron.com/cleaning-and-care/cast-iron/science-cast-iron-seasoning
https://www.cooksillustrated.com/how_tos/5820-the-ultimate-way-to-season-cast-iron
21 december 2020
My personal experience, which is about 40 years worth, is that Crisco All-Vegetable Shortening (the white solid kind, not the oil) works just fine for seasoning. For skillets, muffin or corn stick pans, I simply make a batch of cornbread, melting the shortening in the pan while pre heating the oven to 450, then pouring the extra into the prepared mix instead of the oil called for in the recipe (I always melt extra shortening just for this purpose). For muffin or corn stick pans, I melt the extra shortening in a small cast iron skillet while the oven is pre-heating, which makes it easier and safer to pour into the mix, You can also use the small cast iron skillet to make a small pone if there is too much batter for the corn muffins or corn sticks. The first batch made in an unseasoned pan may not taste right, so it may be discarded (naughty me, so wasteful), but it's only one batch. My cornbread recipe calls for a 450 oven for 20-25 minutes, so it works pretty well time wise. For a Dutch oven and cast iron lids, Crisco shortening is also used, without the extra for cornbread, a 450 oven for about and hour, wiping off the excess after baking and cooling some. Cleaning after that mostly consists of wiping with a paper towel. The muffin and cornbread pans sometimes need a little soapy water to loosen burnt on batter spilled around the edges, but that's it. As always, if using water to clean cast iron, do not soak it for long and immediately dry it after rinsing to prevent rust.
ReplyDeleteOkrathief
I used hot water to clean my cast iron pots and pans, wipe them out and place back on heat to dry up any hidden moisture then apply a thin coat of oil.
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