- Season it properly.
- Never, ever wash it.
Break either rule and you’re not worthy of possessing the pans in the first place.“We don’t really get to use cast iron much in the restaurant,” John rues. Then his eyes brighten, “But we do this seared steak where we heat a cast iron skillet up until it’s smoking HOT, then we throw the steak on and burn the hell out of both sides. Now that is how you sear a steak! We also have a skillet we caramelize onions in.” That’s when the full range of cast iron really hits me: from something as Neanderthal as scorching the bejesus out of red meat to a process as delicate as slowly rendering an eye-watering root into its essential sugars, this pan, when used properly, has magical powers. With a little preparation and maintenance, cast iron cookware will last for generations.
- Rinse any new piece of cast iron cookware and dry it thoroughly (it’s not a bad idea to dry it in a warm oven for an hour or so to ensure that it is thoroughly dry). Once the cookware is completely dry, fill the bottom with coarse kosher salt (Chef John Ondo of Lana is adamant that this type salt be used).
- Use a rag to thoroughly scrub the inside of the pot, making sure to hit the sides as well as the bottom of the interior. The salt acts as an abrasive to smooth the inside surfaces of the pot as well as a cleanser. Dump all the excess salt from the pot (it’s perfectly fine if a little residual salt remains inside the pot).
- Preheat the oven to 350 degrees. While the oven heats, thoroughly coat the entire surface of the pot—inside and out, including the handle—with fat. John prefers to use duck fat (“One of the benefits of working in a restaurant is that I always have plenty of the stuff,” John says). For those of us not so blessed with oodles of the precious commodity, John recommends plain lard, although more industrious cooks with some time on their hands can use fatback, which works wonderfully once rendered into oil. Benighted souls who are squeamish about animal fat can use plain old vegetable oil. Whatever you use, “Don’t just wipe it on the surfaces,” John emphasizes. “Be sure to rub the fat in real good.” Since some of the fat will run off once the cookware is introduced to heat, place the pot on a large cookie sheet to prevent the excess oil from dripping into the bottom of the oven and creating a mess. Place the cookware on the cookie sheet on the center rack of the oven and leave it for 45 minutes.
- After you remove the pot, and while it is still warm, you can use the rag to remove any excess oil, but rub the interior oil well into the pot while it is still hot and the metal is expanded. Once the pot has completely cooled, it is ready to use.
- To clean up, “never, ever wash it with soap and water,” John admonishes. Modern detergents contain degreasers, so using them on seasoned cast iron reverses the seasoning process. Instead, simply heat the pot, introduce coarse kosher salt as you did before seasoning, and scrub the cooking surfaces thoroughly. Dump out the salt and rub in just enough fat (as little as a teaspoon should suffice for a standard skillet) to coat the interior of the pot. If some stubborn food particles stick to the pot after cooking, heat the pot on the stove until the food bits almost start to burn, then scrape up the bits with a spatula and dump them before proceeding with salting and oiling as usual.
If you inherit old cookware or find a piece at an antiques or flea market that has a bit of rust, do not despair. One caveat: some very old cast iron pieces will have tripod feet. Such pots were designed for cooking with coals on an open fireplace and so aren’t adaptable for use on a modern range, but they are ideal for a campfire. A wire brush or fine steel wool applied with some elbow grease should rehabilitate the pot to the point that it can be re-seasoned. After removing all the rust from the pot (both inside and out), simply follow the same seasoning process that you would with new cookware.
Following these simple steps, you will have transformed a new cast iron dutch oven or skillet into an heirloom, or you will have rehabilitated a vintage piece that promises to last for generations.