The microwave, which first became available for conventional residential use in 1967, soon became a standard household appliance across the country and eventually across much of the world. It is an appliance that many take for granted. It is easy and fast, and even people who claim they "can’t cook" can generally manage to use it effectively. Microwaves can be fantastic kitchen tools. They can turn a cold bowl of soup into a comforting winter meal in a matter of minutes; they allow office employees to enjoy a hot lunch in the absence of their home kitchen and make peeling butternut squash a breeze — and let’s not forget about microwave mug cakes!
Most people know that putting metal in a microwave is a big no-no, and it only takes one melted plastic container to learn the difference between plastic that is microwave safe and plastic that is not. But there are some things that do not lend themselves well to being cooked or reheated in a microwave even when there's no metal or plastic involved.
Certain fruits and vegetables, for example, are best cooked the old-fashioned way; that defrosting setting is better left alone; and, as for boiling water, well, stick to the kettle for making tea. But that's not all you should avoid putting in the microwave. These foods and drinks should never go in the microwave.
Anything that's been reheated a few times before
Let’s kick off this terrifying list of things you should never put in the microwave with one that may be obvious but is frequently overlooked. Basically every time you reheat and then cool something that’s already been cooked, you’re detracting from the initial quality of that food. Make sure that when reheating leftovers, you only reheat the amount you are going to use; that way you are less likely to waste perfectly good and delicious food!
Bread
There is never a good reason to microwave bread. It becomes hard, chewy, and revolting; seriously, don't do it. If you want to revive a stale piece of bread, spritz it with a bit of water and pop it into a warm oven to crisp up. You can make wonderful toast in a cast-iron pan if you don’t have a toaster handy. And for leftover pizza that you stored in the fridge (do not eat it if you've left it out overnight), turn to a sheet pan and an oven for a crunchy crust and melty cheese. If you insist on reheating your pizza in the microwave, however (sometimes a hangover is just too overpowering), make sure you reheat it in the microwave correctly!
Broccoli
Most people eat broccoli for its nutritional content. It's really good for you! Broccoli can boost your mood, gives you some protein, and can even help keep your brain sharp and alert. While cooking in the microwave might not have any dangerously adverse effects, it does destroy an awful lot of the beneficial nutrients that many people expect to gain when eating this good-for-you Brassica. Instead, try steaming your broccoli to keep all of those wonderful nutrients alive and kicking.
Brown Paper Bags
You may have seen people using brown paper bags to make their own easy and healthier microwave popcorn. According to the USDA, however, this might not be such great idea, as the bags often contain ink, glue, and various recycled materials might emit toxic fumes when exposed to heat — and could even cause fires.
Chiles
If you have ever cut a chile and then touched your face, you know the power contained within these hot peppers. Although not much happens to the peppers themselves after a spin in the microwave, if you were to try it, you would be in for a nasty surprise when you open the microwave door. The capsaicin, the active ingredient which makes peppers so spicy and affects your metabolism, essentially get vaporized in the microwave, ready to be released like a burning cloud of toxic smog upon whomever removes it from its microwave chamber.
Eggs in shells
You may have heard about making hard-boiled eggs in the microwave — heck, we even have our own recipe for the procedure — but it is a task you should not undertake without knowing the risks. When a whole egg is cooked in the microwave, an appliance that generates heat rapidly, steam forms and builds up inside the egg without having anywhere to go. This means that while it is technically possible to cook an egg in the microwave, it’s probably not worth the hassle or the clean-up after a potential egg-splosion. Better stick to a tried and true method of hard-boiling eggs using a pan of water on the stove. Fun fact: using a microwave doesn’t really cut down on the time it takes anyway!
Fruit
If you have ever been tempted to cook fruit in the microwave…don’t! Grapes will explode like plasma-filled pellets, apples are likely to collapse in on themselves, and raisins could simply ignite and smoke you out of house and home. If you are trying to make a nice compote or quick jam, stick to a classic recipe and you won’t have to deal with fruit burns or smoke bombs.
Frozen fruit
It’s not surprising to learn that many people use their microwaves to defrost frozen fruit. Whether you're making pie fillings, crumbles, fruit desserts, or a cocktail, frozen fruit is a handy ingredient to turn to. But did you know that thawing frozen fruit in the microwave is actually a really bad idea? According to a 2010 study published in the journal Bioelectromagnetics, microwaving frozen fruit can cause beneficial ingredients to be converted into harmful carcinogens — yikes!
Water
A cup or bowl of H20 may seem innocent enough, but boiling water in the microwave can have some dangerous repercussions. Although the appliance may seem like a convenient way to heat water, when you use a microwave for the task, water becomes superheated but is not able to boil (which helps it cool down). This all adds up to disaster if you then add a tea bag or stir the hot liquid- as soon as you add anything, the water will boil, rapidly, and you will risk a nasty scalding session as a result. Better to stick to a kettle to heat water safely and efficiently. There are other ways to misuse your microwave, too; avoid these common microwave mistakes.
