Cure a Cast-Iron Grill
If you purchase a grill with cast-iron grates, curing them before cooking will help reduce the amount of food that sticks to the grates. When curing cast-iron grates, you expose them to a high level of heat with a coating of vegetable oil. Once you have done this, you'll be able to clean your grates after cooking with a stiff wire grill brush.
1 Wash your cast iron grates with soap and hot water to start preparing the grates for curing. Dry them thoroughly with a towel.
2 Preheat the oven to 350 degrees and apply vegetable oil to the grates. Dip a balled up paper towel in vegetable oil and use tongs to hold the towel. Rub the oil-soaked paper towel on the grates, then flip the grates over and do the same on the other side.
3 Line a baking rack with aluminum foil and place the grates on it. To limit the risk of oil dripping onto the heating elements which can result in a fire, place an old cookie sheet under the grates.
4 Leave the grates in the oven for 90 minutes. Wearing oven mitts, remove the grates and reapply vegetable oil. Return the grates to the oven and bake for an additional 90 minutes.
5 Wearing oven mitts, remove the grates from the oven and allow them to cool before using.