How to remove burnt-on grease properly

Why scrubbing doesn't work

When fat is heated past its smoke point over and over, its molecules cross-link into a tough, varnish-like polymer. That layer is bonded to the surface, not resting on it, so abrasion has to grind away the metal's finish to reach underneath.

That is why an hour with a scourer leaves you with a scratched, dull surface that still has brown patches. The bond has to be broken chemically first; after that, removal takes one wipe.

The four-step method

1. 1

   Let the surface cool completely

   Never spray a hot surface. Wait until the surface is cool to the touch, then brush or wipe away loose crumbs, ash and food debris so the foam reaches the grease itself.

2. 2

   Spray an even coat of foam

   Hold the bottle 4–6 inches away and lay down a thin, even layer. The foam is designed to cling to vertical surfaces, so you don't need to soak anything.

3. 3

   Wait about two minutes

   This is where the work happens. The formula penetrates the carbonised layer and breaks its bond with the metal. Very heavy build-up may want 4–5 minutes or a second coat.

4. 4

   Wipe, rinse and dry

   Wipe in one direction with a damp microfibre cloth. Use a soft brush on textured cast iron. Rinse any surface that will touch food, then dry to prevent water spots.

Adjusting for how bad it is

• Light film from recent cooking: two minutes, single coat, wipe.
• Visible brown build-up: four to five minutes, single coat.
• Thick black carbon: coat, wait five minutes, wipe off what releases, then repeat on what's left.
• Years of neglect: expect two or three passes. Each pass takes a layer; do not try to force one pass with a scourer.

Surface-by-surface notes

• Stainless steel: wipe with the grain, then dry to avoid streaks.
• Cast iron: soft brush rather than a cloth, then dry and re-oil to protect the seasoning.
• Porcelain enamel and glass: no abrasives at all — let dwell time do the work.
• Aluminium: avoid alkaline degreasers, which discolour it. Mild soap and patience instead.
• Painted or lacquered finishes: test a hidden spot first.

Common mistakes

• Spraying a hot surface — the product flashes off before it can act, and it's unsafe.
• Wiping too early. Two minutes of waiting saves ten minutes of scrubbing.
• Using a steel scourer on coated surfaces, which permanently ruins the finish.
• Mixing cleaners. Never combine anything with bleach.
• Skipping the rinse on food-contact surfaces.