You could set yourself up for some explosions or worse.
The microwave is a marvel of modern technologyfood can go from ice cold to blazing hot in seconds.
But there are a handful of things that should never be put in a microwave.
Some may even turn toxic.
Just because something bad hasn’t happened doesn’t mean it won’t.
Foods to Never Put in the Microwave
Several foods don’t react well to ultra-fast heating.
Some have compounds that can become irritating, and others might explode due to a build-up of pressure.
Whenchili peppersare heated, especially the ultra-hot varieties, the capsaicin vaporizes into the microwave’s enclosed air.
How to heat:Roast, saute, or grill peppers instead of putting them in the microwave.
Whether in the shell or peeled,hard boiled eggsheated in the microwave release steam.
The steam cannot escape the whites, so pressure builds.
When you cut (or worse, bite) into the egg, the steam is released instantly.
The resulting explosion may burn you.
How to heat:Slice a hard boiled egg into fourths before you heat it in the microwave.
Leftover Potatoes
Don’t worry, you’re able to stillspeed-cook your spuds in the microwave.
Potatoes often houseClostridium botulinum, the botulism bacteria.
How to heat:Reheat in the oven, but don’t bake potatoes in an aluminum foil jacket.
Grapes
Don’ttop your oatmealwith a handful of grapes and slide the whole dish in the microwave.
Grapes become superheated, and the sugary pulp quickly turns into molten plasma.
They also heat quickly in a skillet on a medium-high stove eye.
Tomato Sauce
Heatingtomato saucesin the microwave often ends in splatters.
The steam builds up until it’s powerful enough to burst throughandonto the microwave walls.
How to heat:Heat any sauces in a small pan on the stove.
Here are a couple of liquids where you should take extra careor avoid the microwave altogether.
Water that is heated by itself in a microwave can quickly become superheated.
In rare cases, it might even explode.
How to heat:Let a kettle do the work.
If you don’t have a stove eye readily available, consider an electric option.
Baby Formula or Breast Milk
Microwaving any liquid can cause hot spots due to uneven heating.
Also, some studies suggest that microwaving baby formula or breast milk can degrade some important nutrients.
Always place food on a microwave-safe glass plate or container instead.
Cover with a paper towel and microwave as normal.
It might melt or warp.
And here’s your critical reminder: Never put metal of any kind in the microwave.
Even vintage dishes with a gold gilt on the edges can spark and cause a fire.
Plastic Containers
Some plastic is safer than others when it comes to heating.
As a rule of thumb, double-checkany plastic containerbefore you zap itit should say “microwave safe.”
When in doubt, switch to microwave-safe glass containers.
Why You Should Never Microwave Nothing
Never start an empty microwave oven.
Double-check that you’ve put food in the microwave before you press start.
National Pesticide Information Center.Capsaicin: general fact sheet.
Date Accessed Jan. 30, 2023.
Acoustical Society of America.Microwaved exploding eggs make for an unusual acoustic experiment.
Elfalleh W, ed.PLOS ONE.
2020;15(8):e0237391.
2021;21(1):38-52. doi:10.33103/uot.ijccce.21.1.4
