How to Clean a Microwave Oven
There are few things more disgusting than opening a microwave oven to find cooked-on extraneous matter clinging to every surface. Or unfortunate food explosion. The way to avoid this, of course, is to clean the appliance thoroughly after every use.
Uh-huh. Sure. But let’s get real. A microwave with frequent use, whether at home or at work, doesn’t get a thorough cleaning every single time—after every use. It’s going to get dirty so it’s good to know how to clean a microwave oven almost effortlessly. With acetic steam!
How to Clean a Microwave
You’ll need:
✅ microwavable glass bowl or
measuring cup
✅ water
✅ plain white vinegar* and/or
1-2 lemons or bottled lemon juice
✅ wooden spoon, chopstick, or skewer
✅ sponge
✅ clean cloth or paper towel
Step 1: Prepare
Remove any dish or other container that may be in the microwave. However, as dirty as it may be, leave the round glass tray and that gizmo under it that make the tray rotate in the microwave. You will clean this separately, later in the process.
Step 2: Fill a glass container
Ingredients:
- 1 cup white vinegar, OR 1-2 lemons,
OR both vinegar and lemons - 1 cup water
This is not an exact science, so use what you have on hand—vinegar or lemons or if you have both, great—use both, no specific measurement required. You can eyeball the amounts and proportions!
Pour the ingredients into a microwavable container like a glass bowl or measuring cup. Cut the lemon(s), squeeze the juice into the bowl, and then throw the rinds in as well—if you’re using lemon(s).
The key here is acid—the acetic acid in vinegar and citric acid in lemons. Mixing these acids to boiling is not a problem at all. The acid turbo-charges the effects of super-hot steam to attack all that goo and grime.
As a safety precaution, stick a chopstick, skewer, or wooden spoon in the cup or bowl containing water and vinegar to prevent the unlikely occurrence of exploding water.
Place the bowl or measuring cup in the microwave.
Water Can Explode in the Microwave
This is an all too common example of what can happen. A man decided to have a cup of instant coffee, so he heated a cup of water in the microwave. When the timer went off, he removed the cup from the microwave and noticed that the water had not boiled.
Just then, the water literally “blew up” in his face. His whole face was blistered with first and second-degree burns, which left some permanent scarring and damage to his left eye. While at the hospital, the doctor attending him stated that this is a fairly common occurrence. Water, vinegar, or other liquid alone should never be heated alone in a microwave oven without a wooden stir stick or something non-metallic in the water to help diffuse the energy as it is heating in the microwave.
Why? This phenomenon is known as superheating. It can occur anytime water and or vinegar or other liquid is heated in the microwave especially if the cup or bowl is new. What happens is that the water heats faster than the vapor bubbles can form.
Without bubbles, the water cannot release the heat that has built up, the liquid does not boil, and it continues to heat up past its boiling point. If the liquid is bumped or jarred, it’s enough of a shock to cause the bubbles to rapidly form and the result is an exploding liquid that is scalding hot. The best solution is to place a wooden stir stick or something non-metallic in the water to help diffuse the energy as it is heating in the microwave. — Steve Spangler Science Blog
Step 3: High for 5-10 minutes
The more challenging the situation, the longer you want the water and vinegar to steam away. Keep an eye on it, however, as you do not want the cup or bowl to boil dry.
Step 4: Remove container
Very carefully, using an oven mitt or potholder, remove the container. Notice how all interior surfaces and the inside of the door are dripping wet with hot steam.
Step 5: Remove tray and moving part
Quickly take out the round glass tray and that gizmo thing under it and place these items in the sink, provided your gizmo can be easily removed. If attached, leave it attached.
Step 6: Wipe it clean
While the microwave interior is still hot and wet, using a sponge, cloth, or paper towel, wipe down the oven’s interior. This should be quite easy because the steam has softened and melted every bit of goo and grime. Make sure you clean the “ceiling,” the vents, the walls, and the floor of the microwave. And don’t forget the door!
Step 7: Clean the glass tray
Clean the glass tray in the sink along with the rotating mechanism as needed, wipe dry and return to the oven.
Dear, Dear Mary:
I am so grateful for all you wonderful and absolutely “useful” information you have given us over the years.
ONE QUESTION: Could u put, instead of a cup of water/lemon – a soaking (Water & Lemon) TOWEL – in the microwave. That way decreasing any explosion????? Halena
I suppose you could provided that towel was super drenched. But if you put a piece of lemond rind in with the water/lemon you will prevent an explosion. That will break the surface tension of water alone, which is the real culprit.
I love your info, but I wish it could be pinned to Pinterest!
I love, love, love your tips. I blew up butter in my new microwave. Now the stainless back of microwave looks well stained with dark spots now. Adding to the pain, it is built in and even standing on a chair I can’t reach the back to scrub it. I did purchase a handy plastic little guy with holes in his head which can be used to steam the microwave clean as you describe. It works but still those dark spots.
I accidently found that a cup of boiled water (forgot that I wanted a cuppa) sitting in the microwave for a few extra minutes steamed it all up enough to wipe it down to sparkly clean. But the lemons in the water would make for a nice addition!