Seasoning relies on baking cooking oil or vegetable shortening into cast-iron skillets and pans at high temperatures. It seals interior and exterior surfaces to keep out moisture, prevent rust from forming, and create a smooth, shiny surface that quickly releases cooking foods. Proper cleaning -- rinsing with hot water (soap and abrasives are no-nos), wiping away grime, rinsing, drying, and applying oil -- maintains the cast iron's original seasoned finish and, along with regular use, continually enhances the skillet's nonstick properties.
Cast-iron skillets are sold as unseasoned and factory-seasoned versions, so read product labels before you buy. Those with preseasoned finishes are ready for service and can be used right away to bake a frittata, saute vegetables, or fry chicken. You will need to season cast-iron skillets sold without a factory-seasoned finish by following the steps below. Note that the experts at Lodge Manufacturing, makers of preseasoned cast-iron skillets, say these seasoning steps can be used to refurbish cast-iron skillets and pans that have lost their nonstick attributes and have dull, graying, or rusty finishes.