Clean a microwave you use every day about once a week, and wipe up big splatters (soup, tomato sauce, an exploded egg) as soon as the inside is cool enough to touch. Whirlpool's microwave cleaning guide gives the same weekly rule of thumb. If you only reheat coffee a few times a week, every two or three weeks is fine.
Weekly sounds like a lot for a box you mostly use to warm leftovers. The reason is that microwave mess sets fast. Each time you run it, steam softens yesterday's splatter a little, then the heat dries it again, a bit harder each round. A spot you could wipe off in five seconds on Monday needs scrubbing by Saturday. The worst of it ends up on the ceiling, directly above whatever bubbled over, where you won't see it unless you crouch down and look.
How to clean a microwave with steam#
Steam does most of the work, so you don't need a special cleaner.
- Pour 1 cup of water into a microwave-safe bowl or measuring jug. Add 1 tablespoon of white vinegar or lemon juice if there's a smell to deal with.
- Heat it on high for 3 to 4 minutes, until the window fogs.
- Leave the door shut for a few more minutes so the steam can soak into the dried food.
- Lift the bowl out with an oven mitt. The water is close to boiling, and this is the step where people get burned.
- Take out the turntable and the roller ring under it. Wipe the ceiling first, then the walls, then the floor, using a soft cloth dipped in warm water with a little dish soap.
- Go over everything again with a clean damp cloth to remove the soap, then dry it.
- Wash the turntable in the sink once it has cooled. Hot glass can crack in cold water. Check the manual before putting it in the dishwasher.
The water amount and heating time are Whirlpool's. Some models have a Steam Clean button that handles the heating for you; if yours has a cleaning program, follow its instructions over these.
One caution about the water. Plain water heated in a smooth container can get hotter than boiling without bubbling, then erupt when you move it. The FDA's microwave oven page explains this superheating and says not to heat water longer than recommended. Stick to the time, give it a minute before opening the door, and keep your face back as you lift it out.
Don't skip the door and the outside#
The inside of the door gets as much splatter as the walls, plus a greasy film from steam. Wipe the glass, the inner frame, and the flat strip where the door presses against the cabinet when it closes. Crumbs on that strip stop the door from sitting flush.
For the outside, spray cleaner onto the cloth, not onto the microwave, so nothing drips into the vents or behind the keypad. Wipe stainless steel in the direction of the grain (our stainless steel appliance guide covers streaks). Turn on the control lock first if your model has one, or you'll start it by accident while you're wiping the buttons.
What not to use inside a microwave#
The FDA recommends water and a mild detergent for the cavity, the edge of the cavity, and the door, and says not to use scouring pads, steel wool, or other abrasives. Scratches in the interior finish hold on to grease, which makes every clean after that harder.
A few other things to leave alone:
- The small flat panel on one of the inside walls. That's the waveguide cover. Wipe it gently if it gets splashed, but don't pry it off or soak it.
- Oven cleaner. It's made for a different surface, and you don't want its residue anywhere near reheated food.
- Anything that involves opening the outer case. That's repair work.
Use a cloth or sponge that hasn't just been wiping raw chicken juice off the counter. If your kitchen sponge is past its best, here's when to replace it.
When a dirty microwave is really a broken one#
Sparks, a burning electrical smell, or a door that won't close firmly are not cleaning problems. The FDA says not to run a microwave if the door doesn't close firmly or is bent, warped, or damaged, and to stop using one that keeps running with the door open. Contact the manufacturer or a repair service before you use it again.
How to keep it cleaner between washes#
Cover your food. A vented microwave cover, or a damp paper towel over the bowl, catches most of what would otherwise end up on the ceiling. Stir soups and sauces halfway through so they don't erupt. And wipe the turntable when you see a spill, before the next three meals cook on top of it.
If yours is an over-the-range model, it also has grease filters underneath that catch fumes from the cooktop. Those are a separate job on their own schedule; our range hood filter guide covers washing the metal ones and replacing charcoal ones.
FAQ#
Can you clean a microwave with lemon?#
Yes. Whirlpool's guide uses 1 tablespoon of lemon juice in 1 cup of water, heated the same way as the vinegar method. The lemon helps with smells. The steam is what loosens the food.
Can you use baking soda to clean a microwave?#
Yes. Whirlpool describes stirring several tablespoons of baking soda into a small microwave-safe dish of water and heating it for 5 minutes, then wiping the inside down. It's a good choice when something burned and the smell won't leave.
How do you clean a microwave you've neglected for months?#
Run the steam step twice. After the first round, wipe off what comes away easily, then steam again and let it sit for 10 minutes before the second wipe. Soften the stubborn spots with a soapy cloth held against them for a minute. Don't reach for a scraper.
A weekly wipe is easy to forget because nothing happens if you miss one. Pairing it with another weekly job, like taking out the recycling, or setting a recurring reminder in ChoreLists.com, keeps it from turning into the months-long version.