How to Season Cast Iron Grill Grates

Start with clean, dry grates. If they are new and coated with a protective factory film, or if they have surface rust, scrub them and dry them thoroughly. Any moisture left on bare cast iron will start rusting almost immediately, so make sure the metal is completely dry before you add oil.

Apply a very thin coat of a high-smoke-point oil over the entire surface, then wipe it back off so the grate looks almost dry. The most common mistake is using too much oil, which bakes into a sticky, gummy mess instead of a smooth finish. Thin is the rule: you want a whisper of oil, not a puddle.

Heat the grates until the oil passes its smoke point and bonds to the metal, either in the grill with the lid closed or in an oven. Let them heat through, then cool. Repeating this thin-coat-and-bake cycle a few times builds a more durable layer, but even a single good round is enough to start cooking.

Maintain the seasoning by cleaning gently. Scrape or brush off food while the grates are warm, and avoid soap and abrasive scrubbing that strip the coating. After cleaning, wipe on another whisper of oil while the grates are still warm to reinforce the layer and lock out moisture.

If rust does appear, it is not the end. Scrub the rust away, dry the metal completely, and re-season from bare iron. Treated this way, cast iron grates can outlast the grill they came with and reward you with the deep, even sear that makes them worth the extra attention.