For those who follow our work, there is no surprise that we love to cook with cast iron. However, some people fear cast iron due to the maintenance required to keep this type of cookware in perfect condition. Season cast it's easier than you might think, and to show you that, today we'll teach you how to season cast iron.
If you look online at different cast iron cookware sites, you'll see that there is no consensus. Some swear that flaxseed oil is the best for seasoning, others throw down for Crisco or lard, and still others say that canola is their go-to. The oven temperatures they use are equally varied, and some advocate convoluted methods that involve repeatedly changing the oven temperature during the seasoning process.
The thing is, we here at The Cooking World use our cast iron cookware all the time, and, after testing countless methods, we've found that most of the complex rules of cast iron are nothing more than superstition. To help you understand that it's actually true about cast iron seasoning, we'll show you exactly what we do to maintain our cast iron cookware in perfect condition.
Before we show you how we season cast-iron cookware, it's important to understand what is seasoning after all.
Food sticks easily to a bare metal cooking surface; it must either be oiled or seasoned before use. In this case, seasoning has nothing to do with salt or spices. Instead, it describes a hard, protective coating that's formed by heating incredibly thin layers of fat (like oil) on the cast iron. As the fat is heated, it bonds to the metal and to itself in a process called polymerization, as the fat converts into a form of plastic. After enough layers of seasoning have been applied, what you end up with is not a greasy coating but a hard, blackened skin that protects the metal.
The seasoned surface is hydrophobic and highly attractive to oils and fats used for cooking. These form a layer that prevents foods, which typically contain water, from touching and cooking on to the hydrophilic metallic cooking surface underneath. This is why a well-season cast iron skillet is as good or even better than the best nonstick skillets on the market.
Nowadays, nearly every new cast iron pan you purchase will come pre-seasoned from the manufacturer. This is a good base layer to start with, but we always like to add a few more layers of seasoning.
As we said, seasoning cast iron is pretty simple. Short version, you need to oil the entire pan and then heat it until polymerization occurs, repeating the process to build up a protective layer. By heating the whole pan to a high enough temperature, you permanently bond the oil to the raw iron. In this form, it protects the metal from air and food.
Before you start seasoning your cast iron pan, the first thing you should do is to wash it. Give the pan a good scrub with warm, soapy water, then dry it thoroughly. Even after towel-drying, some surface moisture may remain, so your best bet is to put the pan on a stovetop for a minute or two to drive off any lingering water.
Now that your skillet is clean and shiny is time to rub the entire surface, including the handle, with cooking oil (flaxseed, grapeseed, or sunflower oil). The key here is to rub the oil all over but then buff it so thoroughly that the pan no longer looks even the slightest bit greasy. Even a small amount of excess oil on the pan will end up being sticky after the heating process, which is not the result we’re going for! The pan should look nearly dry once you’re done with this step.
Here at The Cooking World we like to use unsaturated cooking fats, like vegetable, and sunflower oil for seasoning our pans. Not only do we always have them on hand, but they work well and are easier to spread than saturated fats, like shortening or lard.
Some cooks swear by using flaxseed oil, and it does yield good results, but due to its very low smoke point at 225 ºC (437 ºF), note that the baking process will turn your kitchen into a very hazy, smoky atmosphere. Besides that, we´ve found that flaxseed oil tends to flake off with use. We don't recommend it.
Place your skillet, upside down, in a preheated 230 ºC (450ºF) oven upside down and bake for one hour. It may get a little smoky, so keep your kitchen well ventilated. Then let it cool.*
*You can skip the cooling process, but remember that the pan will be extremely hot!
It's during this time that the oil will polymerize and form the first of several hard, plastic-like coatings you'll be laying down.
When the pan is cool, rub it once more all over with the oil, buffing it out as before. Then put it back in the oven for another hour. All in all, you'll want to do this oiling-and-heating process three to four times, or five if you want to take it to the next level, to set down a good initial layer of your own seasoning.
Once you're done, just let the pan cool down. It's now ready for cooking.