Things You'll Need
Aluminum foil or parchment paper
New cast iron pans, skillets and griddles need to be seasoned before use. Seasoning is the process of filling the surface pores of the iron with oils, which build up into a smooth surface layer. The more even the surface, the smoother and more nonstick the griddle becomes. Although new griddles must be seasoned before use, they also continue to season with every use: each time you cook with oil, the pan is seasoned a little more. The quality in a cast iron griddle grows with years of use.
Preheat the oven to 400 degrees Fahrenheit.
Rinse the griddle and dry it. Pour or spoon 1 to 2 tablespoons of any type of vegetable oil, shortening, lard, butter or coconut oil onto it. Rub the oil into the griddle with a clean cloth, making sure it coats the griddle evenly. Use only enough to form a thin coat on all inner surfaces. Don't leave puddles, globs or missed spots.
Line a baking sheet with aluminum foil or parchment paper. Place the griddle on top of the baking sheet, upside down.
Place the baking sheet and griddle in the oven and cook it for 45 minutes.
Remove the griddle using oven gloves. Allow it to cool. Do not run it under cold water or it will crack. Leave the oven on while the griddle is cooling.
Repeat the process of oiling, cooking and cooling two or three more times.
How many repetitions is up to you, but understand that each time you do, it improves the griddle. If you do not have time to repeat multiple seasonings, remember that every time you cook on it, you are seasoning it. The more used and older the vessel, the more seasoned it becomes. After seasoning the griddle may look slightly orange and discolored. This will disappear after the first time you cook in it.
Do not put the griddle on a surface that could melt while it is cooling.