chee gin tan/ iStock/Getty Images Plus via Getty Images
The microwave is incredibly convenient for making meals in a snap, from frozen dinners to guilty pleasure foods like pizza rolls and Top Ramen. On the contrary, some foods are foe to the appliance and shouldn’t be cooked or reheated this way no matter how hungry you are. Most of us know that metal is a no-no, but other eats and the vessels they lie in are less obvious offenders.
We figured we’d start this list off right with an undeniable hazard: aluminum foil. One vital kitchen lesson we learned from our parents is that when metal is placed inside a microwave, the appliance’s radio waves reflect off of it, causing it to burn rapidly and catch fire.
In a perfect world, everything would be eaten right after it’s cooked — but sometimes that’s just not the case. It’s best to reheat only the amount needed because food decreases in quality each time it’s reheated. Leftovers can be stored in the fridge for up to four days. Anything that won’t be used within that time frame should be frozen — unless it’s these foods you should never freeze.
Anyone who has ever tried to revive an otherwise delicious piece of pizza in the microwave knows that this method messes with the crust to a point where it’s nothing but a tough, chewy disgrace. If you need it desperately, and can’t possibly wait for it to crisp in the oven, throw it in the microwave with a half glass of water for 30 seconds and hope for the best.
Similar to pizza, other breads lose their integrity when placed in the microwave, somehow becoming both dryer and softer. An oven is one of the better reheating methods here — or toaster oven if you have one — but if you’re planning to reheat last night’s order cheesy breadsticks via the microwave and you don’t want them to taste like a hardened sponge, place them in there with a half glass of water on the side to help retain moisture.
Broccoli is an incredibly popular vegetable beloved for its nutritional content. While the microwave won’t necessarily change the way your broccoli looks or tastes, one study found that the leafy green can lose 74% to 97% of its antioxidants when microwaved while immersed in water. When steamed or cooked without water, it will retain most of its nutrients.
If you’ve ever cut a chile and then touched your face, you know the power contained within hot peppers. Not only can they spark and cause a fire, but chemicals released from the peppers may cause you to choke and may burn your eyes, just as if you were sprayed with mace.
There are dozens of ways to make an egg, some of which involve the microwave, but if you’re thinking about reheating the hard-boiled variety, think again. Hard-boiled eggs, once microwaved, are likely to explode, but not in the microwave. They have a tendency to detonate minutes later after being poked by a knife or teeth. Yes. The egg can blow up in your mouth.
Grapes are one of the best foods for your brain, but please, don’t put them in the microwave. Researchers found that microwaved grapes produce plasma, creating a brief, fiery explosion. How? The water in the fruit traps radiation wavelengths, which bounce around and concentrate where two grapes meet, creating a strong electromagnetic field and eventually, a spark. For context, lightning, neon signs, stars and rocket exhaust are all plasmas.
You can properly thaw frozen meat in the microwave, but it does come with a caution. Once the temperature of the food climbs above 40 degrees Fahrenheit, it’s susceptible to bacteria growth. If you cook the food immediately after thawing, it’ll kill most of the bacteria, but if you pop the thawed meat into the fridge to grill later, you could make yourself sick.
According to a report by NPR, different leafy greens like kale and spinach can actually give off sparks when cooked in the microwave, yielding a similar reaction to what you'd expect from heating up something metallic.
Microwaving raw carrots might sound like your ticket to an easy weeknight dinner side, but they can actually spark and damage your appliance. Why does this happen? It could be due to the minerals in the soil they’re grown in.
Sometimes the easiest way to prepare a store-bought hot dog is to microwave it. Yeah, your wiener may bloat and split, but it could also send sparks flying like the Fourth of July. This can be due to the uneven mixing of salts and additives inside.
Cooking whole, stuffed poultry in the microwave isn’t recommended. This is because food cooks rapidly in the microwave, and the stuffing might not have enough time to reach the temperature needed to destroy harmful bacteria.
If you’re ordering more takeout or food delivery these days, It may be tempting to reheat last night’s dinner for lunch today in a doggie bag. However, it’s best to transfer your food to a microwave-safe bowl or plate first. Styrofoam may melt and release toxins into your food, as will plastic. Paper-based containers could catch fire, and Chinese takeout boxes typically feature a metal handle, which may cause sparks or flames.
Paper bags are not friends of the microwave. You may be wondering, “How come I can microwave popcorn then?” Well, those bags are safe because they contain a material made to consume radio waves. Other paper bags, like the ones you get at the grocery store to pack lunches, do not, and can release toxins and fumes when warmed. They could also catch fire.
If you don’t want to spend money on Tupperware for meal prepping, you might save cold storage containers like margarine, cottage cheese and yogurt tubs. That’s perfectly fine, but if you need to heat something that’s stored inside, transfer it to a microwave-safe plate first because these materials aren’t approved for cooking, and chemicals can migrate into food.
According to research published in the journal Food Control, microwaving processed meats such as bacon or pepperoni can lead to the formation of COPs (cholesterol oxidation products), which have been linked to coronary heart disease.
If you’ve ever microwaved tomato sauce to go with perfectly cooked pasta, you’ve likely noticed it has a tendency to splatter. This is because heat gets trapped internally. The steam has no way to escape, so it bursts and makes a mess. This can happen with many thick sauces.
Oatmeal is one of the most iconic breakfast foods in America, but what’s not so iconic about it is the fact that it, too, splatters in the microwave. Frequent stirring is the best way to dissipate the steam and prevent messes.
Raw potatoes have high water content, which makes them explode in the microwave because the steam can’t escape through the skin, so pressure builds up and — kaboom. Though there are many other ways to prepare this gut-healthy food, you can poke holes in the sides to avoid detonation if you’re dead set on the microwave.
It certainly takes less time to warm water for tea in the microwave than it does to put a kettle on. Some people have been seriously burned by “superheated” water, or water that’s been heated past its boiling temperature. The water does not appear to be boiling, but a slight disturbance or movement — such as picking up the cup or pouring in a spoonful of instant coffee — may result in a violent eruption with boiling water exploding out of the cup.
If you put a Capri Sun in the freezer to cool it down but forgot to take it out before it froze, do not attempt to thaw it in the microwave. This brand, and many others, use metallic packaging, which will set off a miniature fireworks show in your appliance.
If you’re about to rewarm the best chicken sandwich in America with a toothpick at the center, take it out. Anything that comes to a point can spark and cause a fire, even if it’s not metal.
Keeping your bread in its bag with the twist tie on tight is one of the best ways to make your food last longer, but you wouldn’t put aluminum foil in the microwave, so why would you leave a metal twist tie on bread packaging when reheating? These will spark and could cause damage.
If the avocado you picked up at the grocery store is hard as a rock but you want to eat it ASAP, don’t put it in the microwave. This may soften the flesh of the fruit a little and make it seem ripe, but it won’t be. Say goodbye to the creamy, nutty and buttery fruit you know and love. There is, however, a process to ripen avocados the right way.
There’s no reason that you shouldn’t microwave fish beyond the fact that it’ll make your coworkers upset. It’s an office etiquette mistake you should avoid, and if your office is your home, you should spare your roommates the smell too.
Ah, Peeps — one of the most popular Easter candies of all time. These marshmallow shapes look cute in a basket with fake grass and other sweets, but if you put one in the microwave, it will expand, transforming into something straight out of a horror film. When you take it out of the microwave, it will deflate, becoming dry and crunchy, possibly even turning brown or black on the inside.
If you’ve made coffee at home, you may be tempted to give it a quick nuke before stepping out. Don’t. Most travel mugs are made of material — like stainless steel or plastic — that isn’t meant for the microwave. Luckily, most have incredible insulation that will keep your drink warm for hours.
Baby’s diet is just as important as Mom’s, and if breast milk is on the menu, it’s important to know that it should steer clear of the microwave. The microwave can create dangerous hot spots in bottles of formula or breast milk. Instead, run it under warm water, swirl it around a bowl of warm water or thaw in the fridge. To make sure it’s not too hot, squirt a drop or two on the inside of your wrist before feeding.
That’s right, even microwaving nothing can be harmful, and literally even make your appliance blow up. Without anything to soak up the radio waves emitted when powered up, they bounce off each other and are absorbed by the microwave, causing it to explode. Microwaving mistakes not only decrease the quality of your food, but they can be dangerous too. Using this appliance incorrectly is just the tip of the iceberg when it comes to bad cooking habits you need to stop now.
More from The Daily Meal