A microwave gets dirty in a way nothing else in the kitchen does: a bowl of bolognese erupts, the door closes on it, and three more reheats bake the spots hard. The mess costs you more than appearances. CHOICE points out that food remnants in the cavity absorb microwave energy meant for your dinner, so cooking takes longer and the oven's life may be shortened.
Quick Answer: Stand a bowl holding a cup (250 ml) of water and a few lemon slices — or a tablespoon of white vinegar — on the turntable with a wooden spoon in it, heat on high for 3 minutes, then leave the door shut for 5 minutes so the steam softens the splatter. Unplug, lift out the turntable and roller ring, and wipe with a damp cloth and a drop of dishwashing liquid: roof first, then walls, floor, door glass and seals. Wash the turntable and ring in the sink. Never spray cleaner into the cavity, never use scourers, never run it empty.
Why the Steam Method Works (and What Lemon and Vinegar Actually Do)
Rozita Vaskoska, a microbiologist and senior scientist with CSIRO, told ABC News that the risks from not cleaning a microwave are, in general, very low. You clean it for cooking speed, smell and appliance life, not germs. Dried splatter is dehydrated food, and steam puts the water back so it wipes off.
Lemon or vinegar? As Dr Nathan Kilah, Senior Lecturer in Chemistry at the University of Tasmania, explains, acids such as the acetic acid in vinegar dissolve mineral deposits like limescale, bases break apart fat molecules, and lemon juice is an acid too (citric). So either acid helps lift the cloudy mineral film on the turntable and door glass — worse on the harder water in Adelaide, Perth and Brisbane — and lemon leaves a fresh smell. Neither acid is a degreaser; that is the job of the surfactant in dishwashing liquid, and plain water makes just as much steam. Bicarb soda is a mild abrasive for baked-on spots. Keep it away from vinegar: as Kilah explains, the two react to form water, sodium acetate and carbon dioxide, and the fizz is not what cleans — any work done is by the leftover bicarb and your scrubbing. Use them separately.
Additive | What it actually does | Best for |
|---|---|---|
Plain water | Steam softens dried splatter | Every clean |
Lemon slices | Steam, mild citric acid, fresh smell | Smells, light hard-water haze |
White vinegar (1 tbsp per cup) | Steam plus acetic acid for mineral film | Cloudy turntable or door glass |
Bicarb soda paste | Mild abrasive | Baked-on spots after steaming |
Dishwashing liquid | Lifts grease | Every wipe-down, on the cloth |
What You'll Need
A wide microwave-safe bowl, ideally an older one with a few scratches (not a smooth new cup)
A cup (about 250 ml) of water, plus a lemon or white vinegar
A wooden spoon or chopstick
Two microfibre cloths and dishwashing liquid
A non-scratch sponge and bicarb soda for baked-on spots
A soft toothbrush or cotton buds for the seal groove
No spray bottle: everything goes into the cavity on a cloth.
How to Clean a Microwave Step by Step
Put the steam bowl on first and wipe the benchtop while it works — that is how a professional fits the microwave into a kitchen clean.
Step 1: Steam the cavity (3 minutes on, 5 minutes shut)
Leave the turntable and roller ring where they are: the Breville manual says not to use the oven without the turntable roller and glass turntable in place. Fill the bowl with a cup of water, add lemon slices or, as CHOICE suggests, a tablespoon or two of vinegar, stand the wooden spoon in it and put the bowl on the turntable. Heat on high for three minutes — stop when the bowl is steaming — then, as ABC News recommends, leave the door closed for five minutes so the trapped steam loosens the residue.
The spoon and the scratched bowl matter. Dr Karl Kruszelnicki explains on ABC Science that water in a microwave can pass 100°C without boiling if nothing starts a bubble — which a smooth new cup lacks. A scratched bowl and a non-metal spoon give bubbles somewhere to form; tap the container from a distance before lifting it, and keep your face back.
⚠️ Safety note: Liquids heated in a microwave can become super-heated (past boiling point without actually boiling) and may suddenly erupt when stirred or knocked. Do not overheat the water, stir it before heating and halfway through, avoid straight-sided, narrow-necked containers, and let it stand before lifting it out. — ARPANSA and the Breville Combi Wave instruction book
Step 2: Unplug it and lift out the turntable and roller ring
Pull the plug from the power point — the Breville manual says to remove it before cleaning. Take the bowl out, then lift out the glass turntable and the roller ring (sometimes called the turntable ring) beneath it. Both will be warm, so stand them on the bench: Breville says to let the glass cool to room temperature before washing it or putting it in cold water.
Step 3: Wipe the roof and waveguide cover, then the walls, floor and spindle
Wring the cloth out hard — Breville warns that water must not seep into the ventilation openings — and put one drop of dishwashing liquid on the cloth, not in the cavity. That is the "mild detergent" ARPANSA, Australia's radiation safety agency, specifies for the cavity, door and seals. Start with the roof, so drips land on surfaces you have not cleaned yet.
Somewhere on a side wall or the roof is a rough, cardboard-looking rectangle: the waveguide cover (Samsung calls it the magnetron cover). Samsung's support page explains it is a heat-resistant panel, often mica; removing or damaging it can cause sparking and may void the warranty, and a damaged or heavily soiled cover should be replaced, not removed. Wipe it with a soft cloth and mild detergent under light pressure, never scrub or lift it, and let it dry before the next use.
Then the walls and floor. Wipe around the spindle and dry it; Breville says the roller and floor need regular cleaning so the turntable rotates correctly.
Step 4: Door glass, then the seals
The Breville manual asks for the door and window to be wiped frequently on both sides of the seals with a damp cloth, never an abrasive cleaner. Do the glass, the frame, then the seal and the surfaces it presses against, with the toothbrush along the seal groove. Samsung notes that grime on the seals can stop the door closing properly (see the inspection list below). Haze or crumbs between the door's glass panes are inside the sealed door — not something to open up yourself.
Step 5: Wash the turntable and roller ring
Once cool, the turntable goes into warm soapy water, as the Breville manual specifies. The dishwasher depends on the brand: Samsung says its turntable is dishwasher safe, Breville sends its glass to the sink, so check your manual. Wash the roller ring the same way and, as CHOICE suggests, check its wheels are clean and move freely.
Step 6: Exterior, control panel and the greasy side facing the cooktop
Wipe the outside with a cloth wrung out in warm water and a little dishwashing liquid, then dry. For the control panel the Breville manual says a soft damp cloth with the door left open so the oven cannot switch on; Samsung adds no sprays and no excess water. Vents get a barely damp cloth from the outside only, and the handle is a high-touch surface worth a wipe every time.
The side beside the cooktop or under the rangehood carries a tacky film of settled cooking grease. Two passes with dishwashing liquid on the cloth, then a dry cloth, takes it off. Professionals do this side as part of the cooktop clean so it is never missed, and wipe a stainless finish with the grain.
Step 7: Dry it, refit the parts and leave the door open
Dry the cavity, glass and seals so no water pools around the spindle, seat the roller ring and turntable back in their indents, plug it in and leave the door open for ten minutes.
Baked-On Splatter That Will Not Wipe Off
The fix is more steam, not harsher chemistry.
Steam it again, longer. Run a second bowl and leave the door shut for ten minutes. A spot that survives one short steam rarely survives two long ones.
Then bicarb paste. CHOICE recommends a paste of bicarb soda and water worked gently with a non-scratch sponge. Rinse it off with a clean damp cloth so no grit cooks onto the wall. Keep it off the waveguide cover and door glass, and stop chasing a yellow turmeric stain once the surface feels smooth — it is cosmetic and may never lift.
Getting Rid of a Burnt Smell (Popcorn, Fish and Curry)
The Breville manual gives a manufacturer's odour method: a cup of water with the juice of one lemon in a deep microwave-safe bowl, five minutes on high, then wipe and dry the cavity. Five minutes is long enough to superheat water, so keep the wooden spoon standing in the bowl. CHOICE offers vanilla extract in water as a food-safe alternative. Bicarb or coffee grounds left in overnight is folklore; we found no evidence for it.
If a smell survives two lemon steams, a part has been missed — the roller ring, the spindle or the seal groove. Do those three and leave the door open for an hour. Do not run the oven empty to "burn off" the smell: ARPANSA says never to operate a microwave without food or water inside unless the manual allows it, and Breville says running it empty could damage the appliance.
What Not to Do to a Microwave
ABC News's guide singles out one common mistake: spraying degreaser or harsh chemicals inside the cavity. The manuals explain why, and add more.
Do not | Why | Instead |
|---|---|---|
Spray cleaner into the cavity or vents | May stain or dull the door; water must stay out of the vents (Breville) | Apply it to a damp cloth |
Run it empty | Never operate without a load (ARPANSA); could damage the appliance (Breville) | Always water or food inside |
Run it without the turntable and roller ring | Not to be used without both in place (Breville) | Steam with them in, lift them out after |
Scourers, steel wool, metal scrapers | Pieces can burn off a metal pad and touch electrical parts (Breville) | Steam again, then bicarb paste |
Oven cleaner, caustics, bleach, solvents | Corrosive chemicals may result in radiation leaks (Breville); Samsung says never harsh solvents and to avoid bleach | Dishwashing liquid, lemon, vinegar, bicarb |
Remove or scrub the waveguide cover | Can cause sparking (Samsung) | Soft cloth, light pressure |
Use a steam-cleaner appliance | Not permitted (Breville) | A bowl of water is all the steam it needs |
Keep using it with a bent door or damaged seal | Must not be operated (Breville); repair or replace (ARPANSA) | Technician or replacement |
⚠️ Safety note: Bleach has no job inside a microwave, and if it is ever used on the exterior it must never be combined with vinegar, any other acid, ammonia or another cleaner: household chemicals can create a poisonous gas or liquid when mixed. If fumes are inhaled, call the Poisons Information Centre on 13 11 26. — Better Health Channel, Victorian Government
⚠️ Safety note: Only use a microwave if the door surface is undamaged, the door fits squarely and closes smoothly, the hinges are sound, the door edges and interior surrounds are free of food or burnt material, and there is no corrosion. Otherwise have a qualified technician repair it, or replace it. Routine leakage testing is not considered necessary. — ARPANSA
Rust or flaking paint in the cavity fails that no-corrosion check. That is a technician or a replacement, not a cleaning job.
Grill, Convection and Flatbed Microwaves
A combination microwave reaches real oven temperatures on grill and convection, so the Breville manual says to let it cool entirely before cleaning any part. Once cold, the steam method works as above; wipe fatty splatter after grilling before the next cycle bakes it on. Leave the grill element alone: wipe the cavity around it once the oven is cold and unplugged, and follow your manual for anything more. Breville's Combi Crisp Pan and Trivet go in the top rack of the dishwasher or warm soapy water.
A flatbed microwave has a flat floor instead of a turntable and roller ring, which removes the two parts where crumbs hide. The wipe order is the same.
⚠️ Safety note: Grill and convection microwaves hold heat long after cooking — cool completely before cleaning any parts. — Breville Combi Wave instruction book
How Often to Clean a Microwave
ABC News reports a sensible cadence: spills as they happen, a wipe after steamy food while the cavity is warm, and a proper clean about every two weeks. CHOICE suggests a wipe every few days; Samsung washes the turntable weekly and the roller ring monthly. The monthly exterior, waveguide-cover and door-inspection rows are professional practice, not a published schedule.
Task | How often |
|---|---|
Wipe spills while still warm | After each messy use |
Damp-cloth wipe of walls, door and seals | Every few days to weekly |
Wash the turntable | Weekly |
Steam clean plus the full wipe order | Fortnightly |
Roller ring, spindle, waveguide cover | Monthly |
Exterior, vents, cooktop-facing side | Monthly |
Door and seal inspection | Monthly |
The one habit that halves the work: cover your food
The preventive habit is a lid. CSIRO's microwave safety guidance notes that plated meals can be covered with clean white absorbent kitchen paper to prevent spatter — so yes, a paper towel can go in the microwave for that job — and a microwave-safe lid does the same with less waste. A covered reheat leaves almost nothing to wipe, so the microwave takes a minute in a weekly kitchen routine.
Frequently Asked Questions
Q: What is the best way to clean the inside of a microwave?
Heat a cup of water with lemon slices or a tablespoon of white vinegar for three minutes with a wooden spoon in the bowl, leave the door shut for five, then unplug and wipe the softened splatter off with a damp cloth and a drop of dishwashing liquid, roof first and seals last. Wash the turntable and roller ring in the sink.
Q: Is it better to clean a microwave with lemon or vinegar?
For splatter it makes no difference: the steam does the softening and neither acid is a degreaser. Lemon is better for a fresh smell; either acid lifts the cloudy mineral film on the turntable and door glass in harder-water cities such as Adelaide, Perth and Brisbane. Plain water and dishwashing liquid do the job without either.
Q: Can you clean a microwave with bicarb soda (baking soda)?
Yes, as a paste for baked-on spots after you have steamed the cavity, worked gently with a non-scratch sponge and rinsed off with a clean damp cloth. It is a mild abrasive, so keep it off the waveguide cover and door glass. Use it separately from vinegar, which neutralises it.
Q: How do you get rid of a burnt smell in a microwave?
Use the manufacturer's steam clean: a cup of water with the juice of one lemon in a deep microwave-safe bowl with a wooden spoon standing in it, five minutes on high, then wipe and dry the cavity. Clean the roller ring, spindle and seal groove, where the smell usually lives, and leave the door open for an hour. A smell that survives two lemon steams is a missed part, not a failed method.
Q: Can the microwave turntable go in the dishwasher?
Only if your manual says so. Samsung states its turntable is dishwasher safe, while Breville directs its glass turntable to warm soapy water and reserves the dishwasher for the crisping pan and trivet. Either way, let the glass cool first: Breville's manual warns against putting the hot glass into cold water, and Samsung notes the turntable may still be hot after cooking.
Q: How often should you clean your microwave?
Wipe spills as they happen and give the cavity a quick damp-cloth wipe after anything steamy while it is still warm. Wash the turntable weekly, do the full steam-and-wipe about every fortnight, and check the roller ring, waveguide cover, exterior and door seals monthly. Covering food with a lid stretches every interval.
