8 foods you should avoid cooking in a microwave

The best microwaves are a kitchen staple in many households. They make cooking and reheating foods far easier and quicker than other methods, saving you time and producing versatile tasty meals. But from potential food explosions and nasty bacterial growth to unappetising flavours and textures, there are some foods that you should definitely avoid cooking in a microwave.

Before we get into the full list which is only going to concentrate on food, it’s worth noting that there are other food-related items that should never be placed in a microwave. For example, aluminium foil, takeaway containers, Styrofoam, paper bags and metal cookware are all materials that shouldn’t go in a microwave, as they could catch on fire, release chemical toxins and burn you when you go to take it out. So, please keep this in mind when you go to microwave something.

Now that’s been established, here are 8 foods you shouldn’t cook in a microwave. For more food advice, take a look at foods you should never cook in an air fryer, on a barbecue, in an Instant Pot, in a non-stick pan and in a slow cooker.

1. Fish

Kicking off this list is fish and seafood. We’ve all been there when someone’s brought leftover fish to the office and stunk out the shared kitchen with overpowering fishy smells. But, it’s not just the smell that should put you off putting fish in a microwave. As fish and seafood are quite delicate, they don’t fare well in a microwave as the heat dries them out and makes them tough and rubbery. Of course, there are recipes out there that recommend cooking fish in a microwave but if you’re reheating flaky fish, you run the risk of affecting the texture and flavour.

2. Chicken

Cooking raw chicken or reheating cooked chicken in a microwave is best to be avoided. Can it be done? Technically yes, but it’s not the most safe or conducive way to cook chicken properly. Putting raw chicken in a microwave can cook it unevenly, leaving cold spots in places and allowing bacteria to grow there. As chicken needs to reach a specific internal temperature to kill bacteria, not doing this can result in some parts of the chicken being cooked whereas other parts won’t be, which is dangerous to eat and can cause food poisoning, particularly Salmonella. According to Medical News Today, many cases of Salmonella have been linked to cooking chicken in a microwave, so you’re better off using the best oven or other traditional cooking methods. While you can reheat cooked chicken in a microwave, leaving it in for too long can cause it to dry out, so you’ll need to keep a close eye on it.

3. Frozen & processed meat

Many microwaves have defrost settings so yes, you can technically put frozen meat in the microwave. But one downside to cooking frozen meat in the microwave is that it doesn’t always cook unevenly, meaning you have some parts boiling hot, other parts lukewarm and a few cold spots. As the cooking hasn’t got rid of all bacteria from the food, this can cause food poisoning. Processed meats like hot dogs, bacon and deli meats shouldn’t go in your microwave either, as reheating them can lead to the production of cholesterol oxidation products or COPs. According to Mashed, COPs can be more harmful to arterial cells than pure cholesterol and are more directly connected to heart disease.

4. Hard boiled eggs

Many people love to make scrambled eggs in a microwave, but hard boiled eggs should be avoided at all costs. The heat from the microwave creates steam inside the egg’s shell and the pressure will likely cause the egg to explode. But the worst thing about this is that the explosion tends to happen afterwards, either on your plate or sometimes in your mouth. Not only is this messy but it can burn you, even if the egg is peeled.

5. Bread

For warm bread or rolls, you shouldn’t use the microwave for the job. The heat from the microwave affects the starch and trapped water molecules in the bread which melts and softens the bread. If you eat this straightaway, you’ll notice that the bread is very soggy which isn’t particularly tasty. As the bread starts to cool down, the molecules recrystallise which results in hard and chewy bread rolls… again, not very tasty.

6. Chillies & hot peppers

Regardless of how much you love spice, microwaving chillies and hot peppers is a big no-no. The main reason is because these foods contain capsaicin, an active compound that determines spice level. When heated, capsaicin will be released and fill your microwave with chilli fumes, so when you open the door, the gas can fill your home and hurt your eyes, nose and throat. Eating the chillies or peppers after reheating will also make them much hotter and they could potentially explode, depending on how much heat they’ve been exposed to.

7. Leafy Greens

Raw and leafy greens like kale and spinach might seem harmless, but they’re actually a big safety hazard. When put in a microwave, these greens can release sparks which could catch fire. This is because leafy greens contain high amounts of iron, magnesium and selenium, minerals found in pieces of metal. Cooked greens should be fine in the microwave but if you don’t want your microwave to catch light, raw leafy greens should be avoided.

8. Grapes

Similar to leafy greens, grapes can also ignite in a microwave. Due to the heat and pressure of the microwave, grapes tend to explode, as the sugar in them turns into plasma, which is then expelled around the microwave. This plasma can catch fire inside or outside the microwave which can burn you when you’re taking them out or eating them.