Seasoning is the process of coating the surface of cookware with fat which is heated in order to produce a corrosion resistant layer of polymerized fat. It is required for raw cast-iron cookware and carbon steel, which otherwise rust rapidly in use, but is also used for many other types of cookware. An advantage of seasoning is that it helps prevent food sticking.
Some cast-iron and carbon steel cookware is pre-seasoned by manufacturers to protect the pan from oxidation (rust), but will need to be further seasoned by the end-users for the cookware to become ready for best nonstick cooking results. To form a strong seasoning, the raw iron item is thoroughly cleaned, coated in a very thin layer of unsaturated fat or oil, and then heated until the bioplastic layer forms, and left to completely cool. Multiple layers are required for the best long-term results.
