In the old days, cast iron skillets were always seasoned in a fire before the first use. Today, this can still be done, and it requires no more effort than if you were to season the skillet in an oven overnight. Once properly seasoned, the cast iron skillet will begin to have the no-stick properties for which cast iron is famous.
Build a hot fire in a fire pit or in a charcoal grill using oak, hickory or other hardwood species.
Wash the cast iron skillet. Use a metal scouring scrubber to remove any rust or other grime on the skillet.
Dry the skillet thoroughly using paper towels.
Coat the entire skillet with a thick layer of vegetable oil or shortening. If your skillet has a lid, coat the lid in the same way.
Place the grill grate over the hot fire and set the skillet upside down on the grate. If the skillet has a lid, you can place the coated lid on the skillet and set the skillet on the grate.
Allow the skillet to season until the fire goes out and the cast iron is cool enough to touch with bare hands.
Wash the skillet with clear water and dry it with paper towels. It is now seasoned and ready to use.
You can also season a skillet with a lid by placing the skillet directly into the hot coals after the flames have toned down.
Seasoning a cast iron skillet in the oven is just as simple. Preheat the oven to 250 degrees and place the skillet on the rack and let "cook" overnight.
Always use vegetable oil or shortening to season cast iron. Animal fats, such as lard, can become rancid over time and affect the taste of the foods cooked in the skillet.