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How to season cast iron BBQ grates

Updated: 22 October 2026

Food is sticking, or the bars have gone orange after a wet week in the garden, and you are about to reach for one routine for every grate. How to season cast iron BBQ grates depends on the finish you actually have. Bare iron wants a thin coat of oil and a hot barbecue. Porcelain enamel wants a preheat and a brush, and it does not want the same oil bath while the coating is intact. Neither finish belongs in a dishwasher. The [cast iron grill grate comparison](/hub/grill-accessories/cast-iron-grill-grate) is where the listings sit. Prices are amazon.co.uk listing lines. A qualifying purchase can earn a commission at no extra cost to you.

Food is sticking, or the bars have gone orange after a wet week in the garden, and you are about to reach for one routine for every grate. How to season cast iron BBQ grates depends on the finish you actually have.

Our top picks

CosmoGrill CosmoGrill 4+1, one grate

Best overall

CosmoGrill CosmoGrill 4+1, one grate
9.1/10about £39.99
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CosmoGrill CosmoGrill XL, pair

Best value

CosmoGrill CosmoGrill XL, pair
9.1/10about £32.99
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GFTIME GFTIME 7638, pair

Rank 3

GFTIME GFTIME 7638, pair
9.4/10about £34.19
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On this page
  1. 1.Which routine you need
  2. 2.Bare cast iron
  3. 3.Porcelain enamel
  4. 4.When it goes wrong

Which routine you need

Read the finish field before you open the oil. GFTIME 7638 and Weber 7853 are porcelain-enamel claims. CosmoGrill 90111 sets non-stick to no and dishwasher to no: you oil it, and you do not machine-wash it. SUMNACON and SUMTree are bare plates with rust reports after ordinary washing. Weber 8846 is the awkward page: amazon.co.uk says lacquered and alloy steel, while Weber UK calls part 8846 porcelain-enamelled cast iron. Follow the enamel routine if you bought that part from Weber. Follow bare iron if the bars look raw. Which finish to buy is porcelain versus bare cast iron.

Bare cast iron

Wash a new bare grate with a light detergent so the shipping film comes off, then dry it. Char-Broil’s UK note is that wash, then oil. Do not air-dry. Broil King UK says a wet grid should not sit out, and that a dishwasher is the wrong machine. Use a thin coat. Broil King names avocado, rice bran and canola. Char-Broil names vegetable or canola. Wipe until the bars look almost dry. A thick layer leaves a gummy patch. The BBQ Centre notes that spray oils burn off too cool to build the film. Broil King UK seasons at about 200°C for about 30 minutes. Char-Broil UK burns the oil for about 15 minutes, until it stops smoking. Do not average those into 22 minutes. On gas, lid down, that is a full burner cycle. Let the bars cool, and season again if orange appears.
CosmoGrill CosmoGrill 4+1, one grate

Testsieger

CosmoGrill CosmoGrill 4+1, one grate
9.1/10about £39.99
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Porcelain enamel

Weber UK’s gas cleaning page is the enamel path: burn residue off, brush while hot, and clean cast iron by hand, never in a dishwasher. Part 7522 adds a preheat on high for 15 minutes, then a brush. That is a clean-and-preheat, not Broil King’s 30-minute oil bake and not Char-Broil’s 15 minutes of smoking oil. Weber’s US care article, which is not UK law, says porcelain is not seasoned and that sharp tools chip the coat. The BBQ Centre says you oil the chip, not the whole grate. Once the iron shows through, that spot rusts. GFTIME’s enamel claim still has one rust report after a month. If the grate may not fit, use the cast iron grill grate buying guide before you heat anything.

When it goes wrong

Orange after one cook usually means the grate stayed wet. A SUMNACON review went rusty brown after the first wash even with prompt drying. Wash again, dry with heat, oil thinly, and rerun the cycle. Oil a chipped enamel edge and stop scraping. If a sheet of enamel is lifting, the bare-iron habit applies on that patch only. A cracked bar is finished. One CosmoGrill review reported a crack on the second cook. Replace the grate. A gas smell while you lift it is a gas engineer, not a cleaning step. Check a wire brush for loose bristles, and glance along the bars afterwards. If someone is choking or in severe pain and a bristle may be involved, call 999. If you are unsure and it is not that emergency, use NHS 111. Do not plunge a hot grate into cold water. GLARETEX’s bullets say wait, then soak and wipe dry.

Common questions

Do you season a porcelain grate?
Not while the coat is intact. Weber UK’s routine for these grates is a preheat on high for about 15 minutes and a brush, then a hand clean, never a dishwasher. Weber’s US care article says porcelain is not seasoned and that sharp tools chip it. Oil a chip, which is the BBQ Centre’s advice, rather than coating the whole grate as if it were bare iron. If the listing is lacquered alloy steel on amazon and porcelain on Weber’s own page, follow the finish you can see on the bars.
What oil should you use, and how much?
A thin wipe of a high-smoke-point oil. Broil King UK names avocado, rice bran and canola. Char-Broil UK names vegetable or canola. The bars should look almost dry before you light the barbecue. A heavy pour smokes, smells, and leaves a sticky film. Spray oils burn off too cool to season properly, which is why they are a weak substitute for oil you wipe on. This oil step is for bare iron, and for a chipped spot, not for intact porcelain.
Can you use the dishwasher?
No. Weber UK says cast iron is cleaned by hand and never in a dishwasher. Broil King UK says the same for its grids. CosmoGrill 90111 prints dishwasher as no. One CosmoGrill reviewer put a grate through a cycle anyway. That is an owner experiment, not an instruction, and detergent plus a long wet sit is how a bare grate rusts and how a factory film is stripped. Wash in the sink or on the barbecue, then dry with heat.
When do you brush, hot or cold?
Brush porcelain while it is hot, after Weber’s 15-minute preheat, so residue lifts before it cools into carbon. Bare iron can be brushed hot as well, once you have checked the brush for loose wires, and then oiled when you are ready to season. Do not plunge a hot grate into cold water to speed the clean. Let it cool before a wet wash, which is also what the GLARETEX bullets say: wait, then soak and wipe dry. A thermal shock is a good way to crack a bar.
Are wire-brush bristles a problem?
They are if the brush sheds and a wire stays on the food. Check the head before you use it, and look along the bars afterwards. Medical reports of swallowed grill-brush wires are why that glance matters. If someone is choking or in severe pain, call 999. If you are worried and it is not that emergency, NHS 111 is the next call. A sound brush used with a check is still a normal way to clean a hot grate. A brush that drops bristles belongs in the bin.

Related pages

Weber Spirit cast iron grates

Cast iron grill grate

Porcelain vs bare cast iron grate for outdoor storage

Best cast iron grill grates: listing score and fit

Cast iron grill grate buying guide: year, knobs, size

Sources

Public UK sources used for this comparison. Listing prices, stars and review counts are the amazon.co.uk figures for these ASINs. Retrieved 21 October 2026.

  1. Food contact materials regulations, GOV.UK (retrieved 21 October 2026)
  2. General Product Safety Regulations 2005: Great Britain (retrieved 21 October 2026)
  3. Consumer Rights Act 2015, Part 1 Chapter 2 (retrieved 21 October 2026)
  4. Weber UK: cleaning and maintenance (retrieved 21 October 2026)
  5. Weber UK part 7522 (retrieved 21 October 2026)
  6. Weber UK part 8846 (retrieved 21 October 2026)
  7. Broil King UK: cleaning and maintenance (retrieved 21 October 2026)
  8. Char-Broil UK: prepare a new gas barbecue (retrieved 21 October 2026)