Fish fillets
This isn’t just to avoid being the most annoying person in the office, but also because it ruins the flavor and texture. Fish is way more delicate of a meat than chicken or beef, so it dries out super easily in the microwave. If you want to reheat fish, it’s best to use a pan or the oven.
Chili peppers
Popping these in the microwave could actually get you hurt. Capsaicin, the spicy compound of the chili, is generally considered a chemical irritant to humans (that’s why spice can hurt). When heat is added this compound can release fumes that can really burn your eyes or throat.
Breast milk and formula
Freezing batches of breast milk can be a great way to have regular food for your baby, but don’t thaw it in the microwave. The microwave heat could heat up the milk unevenly and make ‘hot spots’. These hot spots can burn your baby’s mouth or throat, causing potential harm.
Processed meat
According to food scientists, the heat from a microwave can actually result in higher COPs (cholesterol oxidation products) in processed meats than other cooking methods. These COPs are more harmful to arterial cells than pure cholesterol, which is harmful for heart health. It’s best to avoid chucking hot dogs in the microwave for a fast lunch.
Grapes
It seems unusual to be putting grapes in the microwave, but don’t try it out. Putting cut up grapes in the microwave can make them turn into mini antennas for electrical currents in the microwave. Their skin connects these sparks to each other and they can actually create a fire. Crazy.
Tomato based pasta sauce
The mess of exploding sauce can be down to the two main elements: water and tomatoes. Because you have a mixture of water and fiber in one pot, when heat gets added the water turns to steam to get out from being trapped within the fiber, building up a lot of pressure and causing the sauce to cover your microwave.
Left out mushrooms
Mushrooms need to be stored in the fridge within 2 hours after cooking to prevent their protein structure and enzymes from disintegrating. Microwaving mushrooms that have been left out for too long can help the bacteria develop and potentially leave you at risk of food poisoning.
Frozen meat
Using the microwave to defrost your meat can actually be a health and safety issue. The heat from the microwave can cause certain parts of the meat to be hotter than others, and this is where bacteria starts to thrive. The microwave can speed up bacterial growth as it gives them extra warm spots to grow on.
Broccoli
According to the Journal of the Science of Food and Agriculture, cooking broccoli fully in the microwave can strip its flavonoids by 97%, and those are its important anti-inflammatory properties. This creates more damage to these important compounds than boiling, so it’s best to gently cook this veggie on the stove.
Hard boiled eggs
Heating up boiled eggs in the microwave can turn them into a ticking time bomb. If you take a boiled egg out of the microwave and bite or cut into it, it could explode in your mouth or over your hands and leave you with super bad burns due to the yolk being high in temperature.
Left over potatoes
Second day roast potatoes can taste great, but it’s important you store them right before reheating. If potatoes are left at room temp instead of being stored in the fridge, bacteria called Clostridium botulinum can grow, which does not die simply from being nuked in the microwave but could even be made worse.
Bread
Microwaving bread won’t necessarily affect your health, but it will ruin the structure of the bread. The sugar molecules found in starch from the flour will melt and re-harden once cooled, which means your bread will be chewy and hard. Pretty much the opposite of the fluffy and light texture we want from a loaf.
Chicken
Chicken needs to reach a temperature of 165 F in order for it to be safe to eat when cooked. Using a microwave to cook your chicken can really make this hard as it can cook different parts to different temperatures and Salmonella can thrive, causing extreme food poisoning called Salmonellosis.
Cold tea
Did you know certain teas need different temperatures of water? Green tea needs around 170-180 F whereas herbal tea needs 210 F. You won’t get sick from reheating your teas, but it may make it taste bad or weird as you can’t control the water temperature in a microwave.
Kale
Leafy greens like Kale are high in minerals such as iron, magnesium and selenium, the same minerals found in pieces of metal. Left long enough in the microwave, the electric waves in the microwaves could pick up those minerals and send sparks flying inside your microwave.
Frozen berries
The antioxidants found in berries can help fight against diseases and inflammation in the body. However, when they are microwaved for 5 minutes, these important properties can end up diminished and not as effective as they could have been. If you have the time, it’s best to thaw your frozen berries in the fridge.
French fries
There’s nothing more disappointing than soggy wet fries. Microwaves don’t make anything crispy (unless you burn it), and the steam from leftover moisture and oil can take your cold fries from slightly soft to completely floppy. Instead, use an oven or pan to fry them back to life.
Foods that have already been reheated
Reheating food is only a good idea once, and it should be piping hot in the middle. This is because bacteria can start to grow as soon as the food cools, and reheating the food a second time, may not be sufficient enough to kill it. This is why it’s a good idea to reheat portions of food rather than big batches.
Pasta
Leftover pastas can absorb moisture in the fridge, leaving it quite dry. Microwaving it after can increase this problem and leave you with dry and tough pasta. Creamy sauces are also a challenge on pasta, as the oils can separate when reheating leaving the dish quite unappetising.
Pizza
It may seem like the quickest and easiest method to reheat pizza, but microwaving causes the crust and toppings to be soggy and chewy. Reheating melted cheese can also draw out all the oil from it and leave you with a really greasy slice with a soggy crust.
Fried foods
It will never taste the same when popped into the microwave, so just don’t do it. Fried foods will often go super soggy and wet, due to the oil separating. If it’s fried chicken you’re reheating, the crust can also prevent you from reheating the meat to a safe level.
Seafood
Cooking or reheating seafood in the microwave not only makes your entire kitchen or house smell like a fish market, but it also ruins the texture of your food. Squid or calamari for example can turn into the texture of rubber bands, which isn’t what you’re looking for at all.
Left over nachos
Taking your nachos home from the sports bar and reheating them later is a pretty bad idea. By the time you get home, all the moisture from the salsa, sour cream, beans and meat have leaked into the chips. Reheating this can just turn it all into a soggy mixed mess and ruin the texture of each ingredient.
Sandwiches
Heating up cold garnishes and salads makes the sandwich taste super weird. Heating up a toasted sub with fresh salad on it will make the fresh veggies go from crisp and refreshing to dull and limp. If you really need to have your sandwich warm, do your best to remove the salad first.
Rice
Rice is actually one of the most dangerous foods to reheat. Rice can develop a highly resistant bacteria called Bacillus cereus, and it can hide inside the grain. This bacteria can develop even faster when heated up and left out at room temperature, and it can lead to severe food poisoning.
Left over spinach
Plan to heat up your spinach on the stove or in the oven rather than the microwave. Studies have shown that when blasted in the microwave, naturally occurring nitrates in spinach could convert into nitrosamines, which have been studied to be carcinogenic. It’s best to avoid as many carcinogens as possible in your diet.
Blueberries
Similar to other small round fruits, blueberries can be little fire starters in the microwave. Their skin can create a reaction between ionized gas and electricity currents, and form enough plasma that can melt through a plastic container. So if you were planning on warming on blueberries in the microwave, maybe do it on the stove.
Coffee
Reheating that left out cup of coffee you forgot is a bad idea. The radiation and uneven heat from the microwave makes the taste of the coffee taste odd or bad, or even makes it lose its coffee aroma. If you’ve left it too long, it’s best you just brew another cup.
Beets
Beets are super good for you because they are rich in antioxidants and nitrates, which are good for preventing diseases. However, nitrates can turn bad when heat is applied. Nitrate compounds can turn into nitrosamines which can be considered carcinogens, similar to that of artificial sweeteners or red meat.
Turkey
Leftover turkey can make the best addition to sandwiches or salads, so it’s best to just leave it cold. Reheating turkey in the microwave is the best way to completely dry the meat out, as generally turkey is dryer than chicken. Not only that, but it also gets super tough when reheated in the microwave.
Tomatoes
If you’ve not experienced biting into a hot tomato and burning your mouth, you’re one of the lucky ones. Tomatoes are mostly made of water, and this can create a lot of steam inside and outside the fruit. Left for too long and tomatoes can explode or become way too hot to eat, which can cause burns.
Cold pressed oils
Olive oil and flaxseed oils are a great source of omega 3 fatty acids, but these acids are very sensitive to heat. If their temperatures break over 104 F they start to lose their nutritional value and also the taste will be altered. Don’t zap these in the microwave at high temperatures.
Carrots
Carrots are ground vegetables so they may have a bit of soil left around them, especially if you’re buying from a farmers market. This soil can contain minerals, the same kinds as those found in metal. These minerals can react with the electric waves and could start sparks in your microwave.
Water
It’s not a definite rule but more of a safety warning. Because the microwave can heat things up unevenly, ‘superheating’ can occur. This is essentially when the water or liquid becomes extremely hot and above boiling point. It can be hard to see when this happens and can easily cause burns when taking the cup out the microwave.
Steak
Steak lovers will look at you differently knowing you cooked a steak in the microwave. Not only is this just a strange idea, but you can easily ruin an expensive piece of meat. You don’t have much control over the temperature of a microwave, and will very easily dry the steak out.
Raw eggs
Just cook them on the stove. Cooking raw eggs in the microwave can cause them to explode out of their shells and all over your microwave. The raw egg mess will be an absolute pain to clean, but also it will be super hot to touch and could lead to scalding.
Buffet food
You might think bagging up your all-you-can-eat to heat up later is a good idea, but it isn’t. Buffet food is naturally touched by many people, no matter how fresh the restaurant claims it is. It’s also usually kept warm under a lamp, meaning after a few hours bacteria will start to swarm it.
Chocolate
If you’re baking, putting chocolate in the microwave can be a quick way to melt it, but it also goes wrong easily. Melting chocolate this way means you need to stand next to the microwave and check it every 10-15 seconds, otherwise you will end up with burnt and bitter chocolate.
Oily foods
Foods that have a high oil content shouldn’t be reheated in the microwave, as the oil can become a health hazard. If you heat oil past a safe level, which can happen in a microwave as the temperature is hard to control, the oil can release toxic fumes which should not be inhaled.
Boozy warm drinks
Liquor is flammable. Do not reheat any warm drinks you may have added a splash of alcohol to in the microwave, like hot chocolates or coffees. You could risk an explosion or setting your microwave on fire, and microwaves can damage the rest of your kitchen if they burst.