A cooktop griddle transforms your gas or electric cooktop, enabling you to cook multiple pancakes, omelets or grilled cheese sandwiches at one time without juggling several skillets. Typically, cooktop griddles are made of cast metal -- either iron, aluminum or steel. If the surface of your cast metal griddle has become worn, rusted or dull, you can restore the finish by reseasoning it.
If your griddle has been stored improperly, washed with soap and water or air dried, the surface may be rusted. Before you can refinish the surface, any rust must be removed. Rub rusted areas of the griddle with steel wool to wear it away. If the rust is extensive, use medium-grit sandpaper, rubbing in a circular motion. Remove the rust from both sides of the griddle, not just the cooking surface.
Preparation for reseasoning is one of the rare times when you should wash a cast metal griddle with any kind of soap. If the griddle is excessively dirty, you may need to soak it for 30 to 60 minutes. Fill a large sink or basin with hot water and dish soap. Place the griddle in the soapy water, and scrub it with a nylon brush. Allow it to soak, if necessary, then scrub it again under hot running water. Dry the griddle completely with a microfiber cloth.
Cast metal must be seasoned to create a natural non-stick finish. A well-seasoned griddle is black -- this is how it should look. To re-season your cleaned griddle, place it on top of the heating element. Rub the surface generously with melted shortening, lard or peanut oil. Turn the burners on to medium heat. When the griddle begins to smoke, turn off the heat and allow it to cool. Wipe the excess oil off the surface with a paper towel. Alternatively, you can place the greased griddle in a 350 F oven for an hour to season; allow it to cool in the oven, then wipe it off.
Once your griddle is reseasoned, it's important to maintain it properly to prevent it from becoming damaged again. Wash it after use with water only -- soap and detergents will strip the seasoned surface. Always dry your griddle with a cloth or by briefly heating it on the stovetop to quickly evaporate any water on the surface. Before storing your griddle, wipe it with a paper towel moistened with peanut or vegetable oil. Store your griddle in a cool, dry place when it's not in use.