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14 Things You Should Never Put in a Microwave

14 Things You Should Never Put in a Microwave

Things You Shouldn't Microwave

Ah, the microwave. Whether you've got a classic countertop model or one that's built directly into your cabinetry, you've relied on its versatility for every meal and snack of the day. Hot dogs, ramen, soup, macaroni and cheese, steamed veggies, even mug cupcakes and hot cocoa are all some quick bites our mini-ovens can heat up fast. And with the popularity of meal prepping (or making and freezing food for the week in large batches), these appliances are working hard around the clock.

Can I microwave that?

You might even have that quiet, terrible thought as you place your leftovers on the dish and close the door. "Wait, can I microwave that?" Maybe it's because they're so easy to use, or maybe it's because they're always close by--but we sometimes heat up things that we shouldn't. Before you hit the start button, take an extra minute before you nuke any of the following things.

14 Things You Should Never Put In The Microwave

  1. Hot Peppers

    Even if they're not *that* hot, you shouldn't try and irradiate these. Nearly all peppers (with the exception of bell peppers) contain capsaicin, the element that makes them spicy. When exposed to radiation, capsaicin vaporizes into a sort of pepper spray. As soon as you open the oven door, the vapor will fly out...right into your eyes and mouth. If that ever does happen, douse your eyes and mouth in milk to break up the substance.

    If you're still not sold and want to zap your frozen peppers, keep this in mind: hot peppers like jalapenos and habaneros can prove to be fire hazards. Instead, roast them in the oven or sautee on the range. They'll taste better, too. If they could be micro-cooked safely, they'd probably be soggy anyway.
  2. Leafy Greens

    Leafy green veggies have long been lauded for being rich in vitamins and minerals hard to find in other foods….including iron and trace minerals. These are great for building muscle and staying healthy, but not so good for your device. Dark greens like spinach, kale, and swiss chard have metals stored in their stem, and when exposed to radiation, these greens can spark and cause a fire hazard. It might not happen every time, but it only takes one spark to start a fire. If you do have an explosive disaster, check out our microwave buying guide. We'll help you find a new machine for your home.
  3. Hard Boiled Eggs

    While many websites condone it (along with cookbooks of yore), today's modern appliances are not designed to hard boil eggs. Or soft boil them. No matter how soft or firm you want your eggs, they should be made without radiation. Radiation waves and high temperatures can convert to steam inside the egg. As the pressure builds in the shell, it will result in a miniature egg bomb. Whether you're cooking from cold or reheating an egg in the shell that's been cooked already, both have been known to explode. It's better to keep your eggs on the stove, or in a special cooker.
  4. Fruit, Especially Grapes

    Whether you're trying to make a sugary compote, fast-track a jam, or make a mini-pie, it's a good idea to think twice before you nuke any fruit. This is especially true for grapes and raisins. When these heat up, they can explode or ignite. That's because grapes actually turn to plasma, a superheated gas that has been stripped of electrons, when exposed to radiation. Plasma can also be found in lightning and solar wind, and shouldn't be in your appliance or going towards your mouth. Raisins don't explode often, but they smoke instead--possibly due to high sugar content.
  5. Frozen Meat

    Does your appliance have a defrost setting? Most of them do, but that doesn't necessarily mean you should use them to thaw meat. Zapping frozen chicken, beef, and pork can yield uneven results, since some parts may be thicker than others. Unfortunately, heating icy meats can also cause bacteria growth, which can lead to food poisoning. Instead, leave your meats in the fridge overnight to thaw. It'll be worth the extra time and effort.
  6. Water

    This one might be counterintuitive, but if you've ever tried microwaving a mug of water for tea, you'll know it's just not quite right. That's because the radiation can heat water beyond its normal boiling point--a process called superheating. It can quickly become unstable and produce a massive amount of steam, with the potential to burn the unlucky tea-lover. Plus, it can burst from its container, or explode if you add a powder such as instant coffee.
  7. Styrofoam, Takeout Containers

    Even if you've got last night's pad thai leftovers, it's probably best not to heat them up in their styrofoam or coated plastic container. When heated, styrofoam and other plastics release harmful chemicals into your foods--and the microwave as well. And if you have any of those classic Chinese food containers, make sure they don't have metal handles. Metal plus radiation equals explosion. That's because metal deflects radiation waves, bouncing them around erratically.
  8. Breast Milk

    It's important to make sure your baby is getting enough nutrition regularly. That's why it's popular to store breastmilk in the fridge (for up to four days) or even the freezer (for as long as six months). But it's crucial to warm breast milk the right way--and that doesn't involve your microwave. Warming it in here can cause breastmilk to heat unevenly, creating hot and cold spots that can hurt your little one. It especially shouldn't be heated in a plastic bottle, where the tips or bottle itself can melt. Instead, heat these up with lukewarm water, or use a bottle warmer for precision.
  9. Travel Mugs

    While they're great for keeping drinks and soups warm on the go, these travel mugs should never be heated on their own. They're generally made with stainless steel and plastic--both of which are really bad for microwaves. The radiation doesn't truly heat up the liquid inside either--it will only bounce off, ultimately damaging your appliance.
  10. Aluminum Foil

    Probably one of the most well-known "don'ts" of microwaving, aluminum foil and radiation don't go well together. Instead of absorbing heat as food does, aluminum foil reflects it. That makes aluminum foil a damaging fire hazard, so make sure you unwrap your leftovers completely before heating them up.
  11. Fine China

    There are probably a few reasons you shouldn't heat up fine china and older porcelain drinkware. Number one, you're probably not allowed to touch it since your mother thinks you cracked a piece the last time you used a tea cup. More importantly, lots of painted pieces are inlaid with gold, silver, and other metals. Just like leafy greens and tinfoil, the metal in these can cause a spark, fire, or even explosion. Then you'll never get your hands on the familial dishware again.
  12. Brown Paper Bags

    You might think this one's not that big of a deal. I mean, it's just paper, how could that cause a problem? Even popcorn bags are made of paper. But the classic brown paper lunch bag is made differently. Their construction can't stand up to heat very well, and can even catch fire. And even if they don't go up in flames, they can give off toxic fumes, sending germs and exhaust into your food. Instead, pop corn over the stove, or use the provided bag.
  13. Nothing

    Now this one for sure must be a hoax. Right? Microwaving nothing can't be problematic, there's literally nothing to explode or spark. But instead of heating up food, you're actually sending radiation waves into the machine itself, since there's no food to absorb the heat. The components (specifically, the magnetron) can be damaged or break. If that happens, give us a call at 800-860-3577, and we'll help you find a new one that fits your home. Alternatively, head into the store to find a microwave that works for your kitchen.
  14. One Final Piece of Advice…

    We promised you 14 things not to nuke, and our last one is a nearly unnoticeable detail. If you look closely at a tea bag, you may see a small staple holding it together. While you definitely shouldn't throw metal in as a general rule, Lipton Tea Company has done independent studies on this method of tea making--and in their eyes, as long as the staple is submerged, there doesn't seem to be any significant danger. However, just to be safe, it's best to keep your tea bags out of the oven. Plus, tea snobs will drop their jaw when they hear about how you brew your beverages.

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