How to clean bbqs, by brand

The material decides the method, and Australian barbecues use materials that need opposite treatment.

Coated or seasoned

Porcelain-enamelled cast iron is coated. The enamel is a factory-applied glass layer, it is the corrosion barrier, and you cannot restore it at home. You look after it by not damaging it. Never take a wire wheel to it: once the glass is breached the iron beneath rusts and lifts more enamel around the chip.

Bare cast iron is seasoned. The protection is polymerised oil built up through use, it is yours to maintain, and a strong degreaser strips it in one wash. A plate that comes up clean and grey has been stripped, and in a coastal Sydney backyard it will show rust within days. Re-season while hot, with a thin film of high smoke-point oil wiped back until it looks almost dry, then burn it off. Thin is the whole trick: a thick coat turns into a sticky varnish that flakes.

Glossy black usually means coated. Matte grey-black usually means seasoned. If in doubt treat it as seasoned, because that assumption is recoverable and the other is not.

Cast aluminium and caustic

Cast aluminium bodies and lids, found on portable barbecues, are attacked directly by caustic cleaners. Sodium hydroxide reacts with aluminium on contact, fizzes, and leaves the surface etched, chalky and permanently whitened. It is not a deposit that can be polished off, it is the metal itself. Nothing caustic ever goes on cast aluminium, and if a label does not say what is in it, assume the worst.

The grease path

Flare-ups, smoke that smells wrong and a barbecue that will not reach temperature are usually the same fault, and it is almost never the grates.

Fat runs off the food, across a tray or channel, out a drain and into a collection cup. Every stage silts up, and once the drain blocks the tray holds a pool of fat sitting directly over live burners, which is exactly the flare-up people blame on the meat. Do the whole path at least twice a season and most complaints disappear.

Burner tubes and ports

Uneven flame, a burner that will not light along its length, or yellow flame instead of blue, usually means blocked ports rather than a failed burner. With the gas off and disconnected, clear ports with a stiff brush along the tube and an opened paper clip for individual holes, working across the tube so debris is pushed out rather than in. Never drill them out, because enlarging a port changes the gas-to-air mix.

Check the venturi at the control end for spider webs. It sounds like folklore and it is not: certain spiders are drawn to the mercaptan in the gas odorant, nest in the tubes, and the blockage produces a flame burning back at the valve. A yellow flame at the control end rather than at the burner means stop and get it looked at.

Brushes

Wire-bristle brushes shed, and bristles land on the grate and end up in food. Emergency departments see this every summer. A coiled or bristle-free brush, used while the grates are still warm from a burn-off, avoids both that and the enamel damage.