Cleaning a microwave with steam, and keeping it that way

A microwave gets dirty in a way no other appliance does: food is heated fast, moisture inside it turns to steam, and the result sprays outward and bakes onto a hot surface immediately. Scrubbing that off is unpleasant. Steaming it off takes five minutes and no effort.

The method

1. Put a microwave-safe bowl of water inside — around a cup and a half. Add a few slices of lemon, a spoon of vinegar or a spoon of bicarbonate of soda. Any of them work; the water is doing most of the job.
2. Run on full power for four to five minutes, until the water is boiling hard and the inside has visibly fogged.
3. Leave the door shut for a further five minutes. This is the step people skip, and it is the one that does the work — the condensing steam softens the residue.
4. Open the door, take the bowl out carefully — it will be very hot — and wipe the roof, the sides and the back with a damp cloth. Nearly everything should lift without pressure.
5. Remove the turntable and the roller ring and wash them separately.
6. Wipe the door seal and the inside of the door last.

Anything that survives that gets a second round rather than a scouring pad.

The parts people miss

The roof

Splatter goes up. Because nobody looks up, the roof of a microwave is usually the dirtiest surface in it, and it is directly above your food.

Under the turntable

Spills run to the edge of the plate and off. The recess below collects them, and the roller ring collects the rest.

The waveguide cover

The small mica or plastic panel on the side wall. It must be kept clean and it must not be removed — it protects the waveguide. If it is scorched, pitted or arcing, it needs replacing before the oven is used again; it is a cheap part and a genuine fault if ignored.

The door seal

Food residue on the seal keeps the door from closing squarely, which matters for containment. Wipe it, do not scrub it, and never use anything abrasive on the perforated screen in the door.

The vents

Usually on the back or top. Grease and dust block them, the magnetron runs hotter, and heat is what shortens a microwave’s life.

What not to use

• Abrasive pads or cream cleaners. They scratch the interior coating; scratched coating holds food and, on painted cavities, can eventually corrode.
• Oven cleaner. Far too aggressive for a microwave cavity, and dangerous around the waveguide cover and seal.
• Excess water. Do not pour or spray liquid into the cavity — there are electrical components behind the panels. Damp cloth only.
• Bleach. It attacks the seal and the interior finish.

Keeping it clean

A vented cover over food is the whole trick. A plate, a piece of kitchen roll or a purpose-made cover stops perhaps ninety per cent of splatter, and the vent stops steam pressure lifting it off.

Beyond that: wipe spills while the oven is still warm, and stop cooking on maximum power for everything. A lot of splatter is the result of heating a liquid or a sauce far harder than it needs — sixty per cent power for slightly longer produces less mess and better results.

Steam cleaner gadgets

Microwave steam cleaners — the small filled containers that do the same job as a bowl of water — work perfectly well. What they add is a shaped vessel that will not slop, a fixed water volume, and a lid that directs steam. What they do not add is any cleaning power the water did not already have.

They are a convenience, and a reasonable one. The bowl of water is not worse.

When to be concerned

Arcing or sparking, a scorched waveguide cover, a door that no longer closes squarely, or a damaged door screen are not cleaning problems. A microwave with any of those goes out of use until the part is replaced — the door and the seal are what contain the radiation, and they are not the place to accept wear.

Why we write about the boring end

Because the Escondido counter sells microwave cleaners and steam gadgets, and the honest position is that a bowl of water does most of it. Where a product on this site genuinely does something the simple method does not, the listing says what that is.

Common questions

What is the fastest way to clean a microwave?

Boil a bowl of water for four minutes, then leave the door shut for five more. The condensing steam softens everything; most residue then wipes off with a damp cloth and no pressure.

Can I remove the panel on the side wall to clean behind it?

No. That is the waveguide cover and it must stay in place. Wipe the face of it gently; if it is scorched, pitted or arcing, it needs replacing before the oven is used again.

Why is the roof of my microwave the dirtiest part?

Because splatter goes upward and nobody looks up. It is directly above your food, so it is worth checking every time you clean.

Browse the range: all products · about Serve-U-Appliance · ask us a question.