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Scrub the grates clean, dry them fully, wipe on a very thin coat of high-smoke-point oil over every surface, then bake them on the grill at about 400°F for an hour with the lid down and let them cool in place. The heat turns the oil into a hard, non-stick, rust-resistant layer bonded to the iron. Repeat the thin-coat-and-bake cycle two or three times for a durable finish, and re-oil lightly after each cook so the seasoning keeps building instead of wearing off. The whole trick is thin oil and real heat.
What are the exact steps?
Seasoning is simple but order and thinness matter. Work through it once fully on new or bare grates, then maintain with light re-oiling.
- Clean. Scrub off food, rust or factory coating with a grill brush or steel wool. New grates often ship with a protective film that must come off first.
- Dry completely. Any moisture left behind flashes to rust under the seasoning. Heat the grates briefly or towel them bone dry.
- Oil thin. Wipe a high-smoke-point oil over every surface, top and bottom, then wipe again until they look barely oiled. Too much oil is the number-one mistake.
- Bake. Set them on the grill, close the lid, and hold about 400°F for an hour so the oil polymerizes.
- Cool and repeat. Let them cool in place, then run the coat-and-bake cycle two or three times for a hard finish.
Which oil should you use?
The requirement is a high smoke point and a thin application; the exact oil matters less than those two things. A thick coat is what bakes sticky and tacky, so wipe until the grate looks nearly dry before it goes on the heat.
| Oil | Suitability | Note |
|---|---|---|
| Grapeseed | Excellent | High smoke point, hardens well |
| Canola / vegetable | Very good | Cheap, widely used, reliable |
| Flaxseed | Good | Hard finish but can flake if thick |
| Olive oil / butter | Avoid | Low smoke point, turns gummy |
How do you keep them seasoned?
Cast iron grates get better with use, like a well-kept skillet, as long as you feed the finish. Brush a thin film of oil on hot grates before cooking to help release, and after cooking burn off residue, brush clean, and wipe on a thin coat while the grates are still warm so it bonds and seals out moisture before the grill cools. That warm post-cook wipe is what actually prevents rust between uses. Re-do a full seasoning only when the grates go bare, food starts sticking, or you see dull, dry or rusty patches.
Stopping and fixing rust
Rust needs moisture, so your defense is seasoning plus a dry, covered grill. A light oil coat after each cook is the barrier, and a cover on a dry grill keeps rain and dew off — the same moisture control that governs how long a gas grill lasts. Never store cast iron wet or leave it in a damp grill over winter without oiling first. If rust does appear, scrub it back to bare metal with a wire brush or steel wool, wash, dry thoroughly, and season again from scratch — the finish returns completely. For charcoal cooks, well-seasoned grates pair naturally with getting the fire right; see how long a charcoal chimney takes to light.
Buying grates or a new grill? Our best charcoal grill picks note which models come with cast iron grates worth seasoning.
We do not buy, test or physically handle any product on this site. Guidance reflects cast iron care consensus and manufacturer care instructions — see how we rank.
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