Can You Microwave Leftovers Twice? (Explained)

Can You Microwave Leftovers Twice

It’s happened to everyone at least once. You’re cleaning up after dinner and you have some leftovers that you just can’t bring yourself to throw away. So you pop them in the fridge and tell yourself that you’ll eat them tomorrow.

But then tomorrow comes and you’re not feeling the leftover love anymore. You don’t want to waste them, but you also don’t want to eat them cold. So you decide to microwave them. And then you have a second serving.

But is that really a good idea?

Can You Microwave Leftovers More Than Once?

Technically, you can reheat most leftover foods as many times as you want. However, it’s not recommended to do so. Each time you reheat food, it loses some of its nutritional value and becomes less safe to eat.

When food is reheated, it goes through a process of recrystallization. This means that the molecules in the food start to break down and re-form into new arrangements.

The more times you reheat food, the more recrystallization occurs. Not only does this make the food less nutritious, but it can also make it tough and rubbery.

Moreover, each time you reheat food, there’s a chance of bacteria forming. By repeatedly reheating and storing food, the temperature will fluctuate and this can create an environment where bacteria can thrive.

In addition, every time you reheat food, you’re exposing it to new contaminants that can cause illness. So while reheating leftovers may be convenient, it’s also risky.

What Are the Guidelines for Reheating Food Safely in the Microwave?

Here’re a few tips to help you reheat food safely in the microwave:

1. Reheat the leftovers to 165 °F

One of the most important basic food safety rules is to make sure that cooked food reaches a temperature of 165 °F. This temperature is high enough to kill any bacteria that may have lurked in the food.

Use a food thermometer to check the temperature of your leftovers. If they’re not hot enough, pop them back in the microwave for a few more minutes.

2. Cover the food

Whenever you reheat leftovers in the microwave, it’s important to cover them with a lid or a plate. By doing so, you’ll help to retain the food’s moisture and prevent it from drying out.

In addition, the steam that builds up under the cover will help to heat the food evenly, ensuring that it’s piping hot throughout. And, of course, covering your food will also help to contain any splatters.

3. Use the right container

Not all containers are created equal. While some are clearly marked as safe for microwave use, others may not be so obvious.

In general, containers made of glass, porcelain, or ceramic are safe to use in the microwave, as long as they don’t have any metal trim.

However, plastic containers can be more tricky. Some plastics are safe for microwave use, but others can release harmful chemicals into your food when heated.

Also, consider the volume and size of the container in relation to the food. If the container is too small, you may run the risk of spilling or boiling over. It’s best to use a container that is just the right size for your leftovers.

4. Reheat in intervals

When reheating larger portions of food in the microwave, it’s best to do so in short intervals. This will help to ensure that the food heats evenly and doesn’t get cold in the middle.

Start by reheating the food for two minutes, then check the temperature. If it’s not hot enough, heat it for another minute or two. Repeat this process until the food reaches the desired temperature.

5. Deconstruct Your Meal

If you’re reheating a meal that has several different components, it’s best to deconstruct it before microwaving.

For example, if you’re reheating a plate of pasta with sauce, you should microwave the pasta and sauce separately. This will help to prevent the pasta from becoming overcooked or mushy.

The same goes for a meal that has both meat and vegetables. Reheat the meat and vegetables in separate containers to prevent them from drying out or becoming rubbery.

6. Keep it moist

As mentioned before, one of the main dangers of reheating food is that it can become dried out or rubbery. To prevent this from happening, it’s important to add a little moisture back into the mix.

If you’re reheating a dry dish like pasta, add a splash of water or milk before microwaving. This will help to keep the pasta moist and prevent it from becoming overcooked.

For meat dishes, you can add a little broth, gravy, or sauce. This will help to keep the meat moist and flavorful.

7. Spead it out

Spreading the food in an even layer is important when reheating them in a microwave. It allows the microwaves to evenly heat the food, which prevents it from being overcooked in some areas and undercooked in others.

8. Stir it up

it is important to stir them occasionally while they are in the microwave. This helps to distribute the heat evenly, preventing hotspots and ensuring that the food is cooked through.

9. Let it rest

Once the food is heated, let it sit in the microwave for an additional minute or two. This will help to ensure that the food is cooked evenly all the way through.

10. Use caution when removing

It’s important to use caution when removing food from the microwave, as it can be easy to burn yourself. When heated, water molecules create steam, which can build up inside sealed containers and cause them to become hot.

To avoid burns, always use oven mitts or pot holders when removing microwaved food from its container. And be sure to open containers slowly and away from your face, to allow the steam to escape.

How Can You Tell if Food Has Gone Bad After Being Microwaved?

There’s nothing worse than taking a bite of your microwaved food only to find out it’s gone bad. But how can you tell if food has gone bad after being microwaved? Here are a few telltale signs:

  1. The food smells bad. This is usually the first sign that something is wrong. If your food smells off, it’s probably best to avoid eating it.
  2. The food looks different. If your food looks discolored or has changed texture, it’s probably best to avoid eating it.
  3. The food tastes bad. This is the most obvious sign that something is wrong. If your food tastes strange, off, or simply doesn’t taste good, it’s probably best to avoid eating it.

If you notice any of these signs, it’s probably best to avoid eating the food in question. Better safe than sorry!

How Can You Make Sure Your Leftovers Are Safe To Eat?

Storing leftovers may not be the most exciting topic, but it’s an important one. After all, nobody wants to get food poisoning from eating bad leftovers. The key to preventing this is to make sure your leftovers are stored properly.

As a general rule, foods should never be left out at room temperature for more than 2 hours. So if you’re not going to eat them right away, put them in the fridge or freezer.

Use an airtight container or zip-top bag to store your leftovers. This will help to prevent them from drying out or becoming contaminated.

And be sure to label your leftovers with the date they were made. This will help you to keep track of how long they’ve been in the freezer.

Are There Any Foods You Shouldn’t Reheat?

It turns out that there are some foods you shouldn’t reheat. Here’s the list :

1. Rice

Rice, for example, can become unsafe when reheated because of the risk of Bacillus cereus. This is a type of bacteria that can survive high heat and can cause food poisoning.

And it’s not just rice, anything starchy also carries the same risk of having this bacteria. This includes pasta and noodles. So it’s probably best to avoid reheating these types of foods.

2. Vegetables with High Amounts of Nitrates

Although vegetables are a good source of nutrients, some of them shouldn’t be reheated. In particular, vegetables that are high in nitrates.

Nitrates are compounds that occur naturally in vegetables, and they can be beneficial in small amounts.

However, when nitrates are heated, they can convert into harmful compounds called nitrites. Nitrites have been linked to a number of health problems, including cancer.

3. Eggs

Eggs are food that contains a lot of nitrogen. And when they are heated, the nitrogen can react and get oxidized, turning into a cancer-causing substance.

Additionally, reheated eggs just don’t taste as good as fresh ones. The texture changes and they can end up rubbery and gross. So if you’re looking for the best-tasting eggs, make sure to cook them fresh.

4. Chicken

Chicken is a delicious source of lean protein. It’s perfect for a healthy lunch or dinner, and leftovers can be reheated for an easy meal later in the week. However, reheating chicken is not without its risks.

When chicken is reheated, the protein can change and cause digestive issues. Additionally, chicken that has been reheated multiple times can become dry and tough.

5. Potatoes

Eating potatoes are beneficial as they are a good source of fiber, vitamins, and minerals.

However, it is another story when it comes to reheating them as it can carry the risk of producing harmful bacteria known as Clostridium Botulinum. When ingested, this bacteria can cause botulism, which is a serious and potentially fatal illness.

6. Mushroom

Mushrooms are a powerhouse of proteins and minerals, but unfortunately, reheating them can cause problems.

When you heat mushrooms in the microwave, you break down the proteins in them, and this can generate harmful compounds which are formed from oxidized nitrogen and free radicals.

These compounds can wreak havoc on your digestive system and cause a plethora of digestive issues such as nausea, vomiting, and diarrhea. If you intend to store mushrooms for later, it’s best to keep them in the fridge and eat them cold.

7. Cold Pressed Oil

Omega-3 fatty acids are essential nutrients that play a critical role in human health. They are especially important for the health of our hearts and brains. One of the best sources of omega-3 fatty acids is cold-pressed oil like flaxseed oil, olive oil, and canola oil.

However, omega-3 fatty acids are very sensitive to the change in temperature, and when heated above 40 degrees Celsius, they can become rancid and produce harmful compounds. Therefore, it is not advisable to reheat cold-pressed oil.


So is it technically safe to reheat food? Technically, yes. But is it recommended? Absolutely not. Each time you reheat food, you’re essentially cooking it again and that can lead to nutrient loss and decreased safety.

If you must reheat food, do so only once and make sure to heat it until steaming hot throughout to kill any harmful bacteria. When in doubt, throw it out! Your health is more important than any meal.

By Rosie Elliott

I’m Rosie. I’m a professional chef with experience in Western, Mediterranean, and Italian cuisine. I’ve been cooking for over 15 years, and I have two daughters that keep me busy!