24 foods you should NEVER cook in the microwave

Not-so convenient foods

The microwave is a modern marvel, making short work of mealtimes and getting food on the table in a flash. But while some ingredients are perfect for zapping in the microwave, others should definitely stay away from this handy appliance. From chilli peppers to hard-boiled eggs, these foods could spell disaster if you cook them in the microwave.

Read on to discover the foods you should never put in a microwave, counting down to the most dangerous of all.

We've based our ranking on how risky it is to microwave each food, and on the opinions of our well-travelled (and well-fed) team. The list is unavoidably subjective.

24. French fries

It isn't a health hazard to reheat French fries in the microwave, assuming they're no more than a day old. The real problem is how this method of cooking ruins the texture and flavour of the dish. There are few quicker ways to destroy the integrity and crunch of a crispy French fry than to buzz it in the microwave for a couple of minutes. Be patient and reheat your fries in a low oven instead.

23. Breaded or fried food

The whole point of breaded or fried food is that the outside is crispy and delicious, while the inside is soft and juicy. So, if you happen to have some leftover chicken tenders or fish fingers, don't even consider popping them in the microwave – unless you want to lose all of that crispy goodness. These foods are best reheated in the air fryer or the oven.

22. Pasta

Leftover cooked pasta tends to suck up sauce in the fridge, becoming dense and stodgy, and it'll dry out even more if you heat it up in the microwave. You'll also find that a creamy pasta sauce is more likely to separate when it's reheated, making pasta a particularly tricky proposition when it comes to leftovers. Your best bet is to put the pasta and sauce back on the stove with a bit of added moisture – water and oil for tomato-based sauces, and dairy for creamy sauces.

21. Pizza

It’s practically a crime to throw pizza away, but saving a slice for the next day throws up a classic conundrum. Do you have it hot or cold? Some people love it cold for lunch, but others can’t stand it. If you want to reheat pizza so it's still crispy and gooey, do it in the oven. Microwaved, the dough becomes soggy, and the toppings become irredeemably squishy and chewy.

20. Bread

Nothing beats the smell, taste and texture of warm bread fresh out of the oven. But even though it's tempting to try to recreate that sensation by warming bread in the microwave, the process will often leave your favourite carb tough and chewy. This is because of the sugars inside the bread softening and then hardening. For best results, reheat your bread in the oven instead.

19. Pies

Never reheat a pie in the microwave if you want to enjoy it with a crispy top and a piping-hot interior – the dough will inevitably get soggy and probably slump right into the filling. Pies are generally so chunky that it's hard to heat them evenly all the way through, so play it safe and stick to a warm oven.

18. Seafood

Chefs will tell you that seafood doesn't belong anywhere near the microwave. It's far too delicate for the intense heat of the appliance and will almost always end up being very dry and rubbery. Leftover fish and seafood is best eaten cold, sprinkled over a salad, perhaps, or stuffed into a sandwich.

17. Broccoli

Registered dietician Amanda Holtzer told the New York Post that foods rich in vitamin C – such as broccoli, berries and leafy greens – are no good in the microwave. The problem is that the heat from the microwave destroys vitamin C, taking away any health benefits you might have got from it. In Holtzer's opinion, these foods are best eaten raw – or steamed, in the case of broccoli.

16. Plastic trays

Microwave meals, ready meals, TV dinners – no matter what you call them, you should avoid microwaving them in the plastic trays that they come in. Although these containers are technically microwave safe, experts say there's a risk that chemicals from the plastic could contaminate your food, causing problems for your health. Decant the food into glass or ceramic containers instead.

15. Grapes

Leaving aside the question of why you'd ever want to microwave grapes in the first place, there's one very good reason why you should definitely avoid it: grapes spark and explode in the microwave. Don't try this at home, but a viral video from 2011 proved that a grape cut in half and opened like a book will basically blow up when zapped in a microwave. There's a scientific reason for this, but the moral of the story is just to enjoy your grapes cold from the fridge.

14. Frozen meat

We all know the best way to defrost meat is to pop it into the fridge overnight. But on those occasions when you need to defrost it fast, the microwave looks mighty tempting. Resist the urge to blitz the frozen protein, though, because the microwave won't defrost the meat evenly and will leave the exterior tough and rubbery. Consider swapping out your meal choice instead.

13. Cooked chicken

It's perfectly safe to reheat pieces of cooked chicken in the microwave, but you do sacrifice taste for the sake of convenience. The fats in the chicken can oxidise in the fridge – and that sucks out all the moisture from the meat as soon as it feels the heat from the microwave. A better idea would be to eat leftover chicken cold in a salad or a sandwich.

12. Steak

It's perhaps rare to find yourself with leftover steak; however, if you do, keep it away from the microwave. The powerful heat from the machine will dry out the meat completely, leaving it with a rubbery texture that nobody wants. Worse, the reheating process isn't perfect and will often leave some parts overcooked and others cold.

11. Cooked rice

In some circumstances, cooked rice can be reheated safely. If leftover cooked rice has been stored in the fridge for less than 24 hours, it can be safely reheated and eaten once, as long as it's steaming hot all the way through. However, leftover rice that's been stored for too long or has already been reheated could give you food poisoning. Be particularly cautious of takeaway rice, because you don't know how it has been prepared.

10. Tomato-based sauce

Thick tomato-based sauces are delicious any day of the week, but they can make a mess in the microwave. The problem is that steam gets trapped in the sauce, causing bubbles that explode and spray tomato splatters onto the inside of your machine. Worse, the bubbles might not explode until you open the door – sending a splodge of boiling hot sauce onto your skin. Next time, use a vented cover or just reheat the sauce on the stove.

9. Nothing

Never turn on a microwave with nothing inside it. With no food to absorb the microwaves, the magnetron (which makes the microwave work) will essentially absorb the waves and could self-destruct. The worst-case scenario is that the microwave totally breaks down, but even a little damage could mean a trip to the shop for a new appliance.

8. Chilli peppers

You have to be careful with chilli peppers at the best of times, so don't make the mistake of putting them in a microwave. It could potentially cause the peppers to release the fiery chemical capsaicin, which could, in turn, start to overheat. The result? A face full of spicy fumes when you open the microwave door. Stick to frying or roasting the peppers instead.

7. Kale

Zapping dry kale and spinach in the microwave for too long could lead to a disastrous end for your kitchen appliance. The food could potentially get singed or even start a fire if not properly prepared. For best results, rinse the kale in water and place it in a microwavable container with a lid (or wrap it in cling film). This will let the leafy greens steam gently instead of catching fire.

6. Processed meats

Here's a new term for you to worry about: cholesterol oxidation products, or COPs. These can be harmful to human health, potentially leading to hardened arteries and coronary artery disease. What does this have to do with processed meats like bacon and sausages? Well, a 2015 study revealed that microwaving processed meats resulted in higher production of COPs when compared with other cooking methods. So, perhaps it's best for processed meats to skip the microwave and go straight to the pan.

5. Stuffed poultry

Unsurprisingly, the US Department of Agriculture doesn't recommend cooking whole, stuffed poultry in the microwave. This is because, contrary to popular belief, microwaves don't cook food from the inside out. Instead, microwaves penetrate food to a maximum depth of 3.8cm (1.5in), meaning the outside of the chicken would be done before the stuffing had time to cook and destroy any harmful bacteria.

4. Raw carrots

If you've ever accidentally left kitchen foil in a microwave, you'll be familiar with the shocking sparks that can happen once the machine gets going. This is known as arcing, and it can happen with food, too. Strangely, raw carrots that contain minerals from the soil they were grown in will cause arcing, too. It's probably best not to take the chance and find another way of cooking your carrots.

3. Hot dogs

Arcing – when sparks literally fly inside the microwave – is to be avoided at all costs, and unfortunately, that means keeping your hot dogs out of the microwave. According to the US Department of Agriculture, hot dogs contain an uneven mix of salts and additives that can cause arcing and damage to your microwave. To be on the safe side, stick to boiling or grilling your dogs in future.

2. Plain water

Erupting is something you have to worry about if you're heating plain water in the microwave. It happens when the microwave pushes water beyond its regular boiling point of 100°C (212°F). This becomes a major problem when you add coffee or tea to the super-hot water, causing it to erupt or boil over. In the worst cases, simple movement can cause water to erupt – increasing the chances of your skin getting burnt.

1. Hard-boiled eggs

Making a hard-boiled egg in the microwave is fine (if you follow a recipe) – but once that egg is cooked, leave it be. If you try reheating a hard-boiled egg, chances are the microwave will create a lot of steam within the egg and, well, it might simply explode. Perhaps more worryingly, it could be so hot inside that it'd seriously burn your mouth if you bit into it.

Now discover the common foods you should never cook in an air fryer