30 Foods You Should Never Put in the Microwave
Microwaves are a convenient way to heat up food in a flash, but not all fare well in them. There are some ingredients that react poorly to heat waves, causing messes, texture changes or even safety risks.
While microwaves can be a lifesavers on busy days, knowing what not to use them for helps you avoid accidents and wasted meals. The following at 30 foods you should never nuke.
Raw Meat
Microwaving raw meat can cook the outside unevenly while leaving the inside cold. This creates a risk for bacteria like salmonella. If you're thawing meat, use the defrost setting and cook it immediately afterward. For even cooking and better flavor, it’s best to use the oven or stovetop, instead.
Water
Surprisingly, water can be risky in the microwave because of a phenomenon called "superheating." When water heats without bubbles forming, it can reach temperatures above the boiling point while still appearing calm. Once the container is moved or a spoon is inserted, the water can erupt violently and splash scalding liquid.
This is why experts advise heating water carefully and using containers designed for microwave use.
Breast Milk or Baby Formula
Heating up breast milk or baby formula in a microwave is strongly discouraged by health experts. Microwaves heat liquids unevenly, which can create dangerous “hot spots,” even if the bottle feels only warm on the outside. These concentrated pockets of heat can burn a baby’s mouth and throat.
Pediatric guidance typically recommends warming bottles by placing them in warm water, instead.
Butter
Butter melts extremely quickly in the microwave and can splatter if overheated. Since it contains both water and fat, the water portion may heat faster and create small bursts of steam. This can cause the butter to pop or spray inside the microwave.
Using shorter heating intervals and stirring frequently helps prevent overheating.
Hot Peppers
Heating chili peppers in the microwave releases capsaicin (the compound that makes them spicy) into the air. When you open the door, it can cause burning eyes or coughing. The heat also intensifies the spice, making the peppers unpleasant to handle.
Instead, cook peppers on the stove or roast them in the oven to stay safe.
Processed Meats
Processed meats like bacon, sausage and deli meats may undergo chemical changes when heated in a microwave. Research has found that microwave heating can promote the formation of cholesterol oxidation products, compounds associated with heart disease risk.
In addition to potential health concerns, microwaving processed meats often results in uneven cooking and poor texture, compared to stovetop or oven preparation.
Carrots
Carrots may seem harmless, but they can occasionally spark in the microwave - really! This phenomenon occurs because small amounts of minerals absorbed from the soil can react with microwave energy, producing tiny arcs of electricity. While it doesn’t happen every time, sparking can damage the microwave or even start a fire in rare cases.
Cooking carrots with a bit of water and covering them properly can help reduce this risk.
Whole Onions
Microwaving whole onions can cause them to burst or cook unevenly. Like many foods with dense outer layers, the onion’s skin traps steam as the inside heats rapidly. When that pressure builds up, the onion may split open or even pop, creating a mess in the microwave.
Even when they don’t burst, whole onions rarely cook evenly in a microwave - the outside can become soft, while the interior remains firm. For better results, food experts recommend slicing onions before heating, so the steam can escape and the heat distributes evenly throughout the vegetable.
Bread
Microwaving bread makes it rubbery and tough, instead of soft and warm. The heat changes its starch structure, causing it to dry out almost immediately. If you want your bread to be crispy and toasted, use the oven, instead. If you must use a microwave, heat it only for a few seconds and eat it right away.
Rice
Rice is another food that doesn’t always reheat well in the microwave. If it isn't stored properly once cooked, it may contain spores of a bacterium known as bacillus cereus, which can cause food poisoning. Microwaving may not heat the rice all that evenly enough to destroy these toxins.
Reheating rice thoroughly on the stovetop and ensuring it's stored safely in the refrigerator can reduce this risk.
Mushrooms
Mushrooms can become rubbery and lose their flavor when reheated in the microwave. Their delicate structure breaks down quickly under intense heat, leading to a watery texture. Additionally, they contain proteins that degrade when repeatedly reheated, which can affect taste and digestibility.
For the best results, mushrooms are usually best eaten freshly cooked or reheated gently on the stove.
Whole Potatoes
Microwaving whole potatoes without poking holes in them can lead to explosions. Steam builds up inside the skin and bursts once pressure gets too high.
To cook them safely, pierce the potatoes several times with a fork to let the steam escape - or, if you have time, bake them in the oven for a crispier texture.
Fried Foods
Microwaving fried foods rarely produces good results. Microwaves reheat the interior quickly, but leaves the crispy coating soft and soggy. Because they heat food primarily by exciting water molecules, the moisture in fried foods causes the once-crisp crust to steam, instead of stay crunchy.
Reheating fried foods in an oven or air fryer helps restore their original texture.
Steak
Steak is another food that tends to suffer when reheated in the microwave. The intense heat causes the meat fibers to tighten rapidly, leaving the steak tough and chewy. Microwaving also struggles to reheat thick cuts evenly, which may result in an overcooked exterior and a cool interior. A skillet or oven reheating method typically preserves the flavor and texture far better.
Milk
Heating milk in the microwave can lead to uneven temperatures and scorching. Some areas may become extremely hot, while others remain lukewarm, which can affect flavor and texture. In addition, overheated milk may form a skin or foam that changes the consistency of the drink. Warming milk slowly on the stovetop allows for more even heating.
Leafy Greens
Some leafy greens, especially those high in nitrates like spinach or kale, don't handle microwaves well. Reheating them can cause the nitrates to convert into potentially harmful compounds. They also wilt quickly, losing their flavor and texture.
Pasta Without Sauce
Plain pasta often dries out when reheated in the microwave. Since they heat water molecules quickly, pasta can lose moisture and become tough or sticky. Without sauce or added liquid, the noodles may harden around the edges while remaining cool in the center.
Adding a splash of water or reheating pasta in sauce can help distribute heat more evenly.
Cheese
Cheese can behave unpredictably in the microwave. Some melt rapidly and become greasy, while others may harden into a rubbery texture. This happens because microwaves heat fats unevenly, causing the oils to separate from the proteins.
For dishes that rely on smooth, melted cheese, using an oven or stovetop usually produces better results.
Hard-Boiled Eggs
Microwaving hard-boiled eggs can cause them to explode. The steam trapped under the shell builds up pressure until it bursts, often after you've removed it from the microwave. This isn't just a messy endeavor - it's also a dangerous one.
It’s best to reheat eggs by cutting them up first or using a gentler stove-top method, instead.
Hot Dogs
Hot dogs can split open when microwaved, due to steam building inside the casing. In some cases, additives and salt concentrations in processed meats may also cause sparking inside the microwave.
While microwaving hot dogs is common, experts recommend piercing them first or using a stovetop method to prevent bursting and ensure even heating.
Whole Tomatoes
Whole tomatoes can explode in the microwave because their skins trap steam. As the interior heats up, pressure builds under the skin until it bursts. The result is a messy microwave interior and potentially hot splatters that can burn skin. Cutting tomatoes into pieces or piercing the skin allows steam to escape safely.
Whole Apples
Microwaving a whole apple can cause it to burst. Why? Because the skin traps steam as the fruit heats. Apples contain a high amount of water, and when that moisture rapidly turns to steam inside the microwave, pressure builds under the skin. Eventually, the apple can split or explode, leaving a sticky mess inside the appliance.
Even if it doesn’t burst, whole apples tend to heat unevenly, with hot outer layers and a cooler center. If you want to warm apples for desserts like baked apples or oatmeal toppings, it’s best to slice or pierce them first, so steam can escape and the heat distributes more evenly.
Sauce with Oil or Cream
Creamy sauces and oily dishes can separate and splatter when microwaved. The fat heats faster than the liquid, causing the food to cook unevenly and make a mess.
Reheat creamy foods gently on the stove over low heat, stirring often. This keeps the sauce smooth without creating a greasy texture.
Citrus Fruits
Citrus fruits like oranges or lemons may burst if heated whole in the microwave. Their thick skins trap moisture and steam, creating pressure inside the fruit. When the pressure finally releases, the fruit can split or explode.
If you want warm citrus for cooking or beverages, slicing it first is a safer option.
Dense Baked Goods
Dense baked goods like muffins, cakes or pastries often turn tough in the microwave. Instead of gently warming, the microwave rapidly drives out any moisture, leaving the baked item dry or rubbery.
While a few seconds of heating can soften them slightly, longer microwave times usually degrade the texture. A toaster oven or regular oven produces a much better result.
Thick Condiments
Thick sauces like chili sauce or tomato paste can splatter when microwaved. Since they're so dense, heat builds underneath the surface and forms hot pockets of steam. When the sauce is stirred or disturbed, the trapped heat can erupt suddenly.
Covering the container loosely and stirring frequently can help prevent messy accidents.
Grapes
Grapes can quickly overheat in the microwave and actually spark or catch fire! Their skin and moisture content create tiny electrical arcs, which can damage your appliance. Even slicing them doesn't completely remove the risk.
If you want warm fruit for a recipe, heat them on the stove or in the oven where temperatures are easier to control.
Chicken with Skin
Microwaving chicken with the skin on often leads to poor texture. The skin becomes rubbery, instead of crisp, because microwaves don't produce the dry heat needed to brown it. In addition, uneven heating can leave parts undercooked, which is a concern with poultry.
Baking or pan-heating is generally safer and produces better flavor.
Seafood
Seafood tends to overcook quickly in the microwave. Fish and shellfish contain delicate proteins that can toughen rapidly when exposed to intense microwave heat. The result is often a rubbery texture and a stronger odor than when they're cooked using gentler methods.
For better results, seafood is typically reheated slowly on the stovetop or in the oven.
Be Cautious When Using the Microwave
Microwaves are useful tools, but they're not right for every food. If you aren't careful, the wrong items can create hazards or ruin your meal.
A few extra seconds of caution can keep your food safe and tasty (and your appliance in good shape).
