Why is it Bad to Reheat Leftovers Multiple Times? (Safety Tips)

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Nobody likes wasting the food they prepare, so many prefer to store leftovers and reheat them later. That’s a great way to save money and make the most of your groceries. Yet, most people don’t realise that it’s terrible to reheat the same leftovers multiple times.

Reheating leftovers repeatedly is terrible because the quality of the food drops with each reheating. Besides that, unsafe storage of leftovers can lead to bacterial growth that could make you fall ill. Certain food items are also dangerous to reheat even once, like seafood, potatoes, or oily food.

To help you understand this issue better, we’re going to look at everything you need to know about the dangers of reheating your leftovers multiple times.

How Many Times Can You Safely Reheat Food?

Firstly, it’s important to note that there is no fixed number of times you can safely reheat food. But even though you can heat the same food multiple times, the more often you do, the lower the quality will be. Besides that, it depends on how the food is stored and whether it’s home-cooked or takeaway food.

How To Store Food Safely To Reheat Later

Whether your food is cooked at home or bought from a restaurant, it’s always safest to cool and store the food as soon as possible. To be exact, food should be stored in the fridge within two hours of when it was cooked.

The reason for that is pretty straightforward: germs and bacteria can multiply very quickly on food when it’s left at room temperature. Storing food at low temperatures in the fridge will slow down or stop bacterial growth and make the food last longer.

To do that effectively, your fridge should be set at 40° Fahrenheit (5° Celcius) or lower. The closer it is to room temperature, the faster the food will spoil!

Restaurant or Takeaway Food

Couple eating takeaway food

When it comes to reheating home-cooked food, you generally have less to worry about. That’s because you were there for every step of the cooking process and know when it was cooked and how it was stored.

However, special care is needed when storing food or takeaway food to reheat later. Simply put, you don’t know where that food has been or how long it was left out before they served it to you. To be safe, you’ll want to refrigerate that food without any delay and try to avoid reheating any of it more than once.

Eat Immediately After Reheating

No matter where the leftovers came from or how you reheat them, here’s one more way to reduce any risks you might face: serve and eat the food immediately. Don’t let the food sit around after you’ve taken it out of the fridge and reheated it because that could allow bacteria to grow as the food returns to room temperature.

What Are Safe Methods For Reheating Food?

At this point, it’s clear that reheating food too many times is risky. However, the risks aren’t just determined by how you store that food or how many times you reheat it. It’s also about the methods that you use to do so. 

Here are a few tips on reheating your leftovers safely with a stove, oven, and microwave. Plus, we’ll also look at methods that are dangerous for reheating certain kinds of food items.


Using a stove, the best way to reheat leftovers is in a pan. Your goal here is to heat the food thoroughly, preferably to about 165 degrees Fahrenheit. That way, most (if not all) of the bacteria would be eliminated, and the food will be safe for consumption.


Ovens are excellent for reheating leftovers because the heat is transferred to the food items equally from all directions. The oven temperature should be set to at least 325 degrees Fahrenheit. The food item’s temperature should reach at least 65 degrees.


Microwaves are convenient, but they’re not always the best to reheat leftovers thoroughly. Quite often, you’ll need to stir and rotate the food to ensure that it’s been reheated all the way through. As you might know, heating food in the microwave might leave the food cold right at the centre even though the outside is piping hot.

Dangerous Methods For Reheating Food

Some methods for reheating food are dangerous simply because they heat up the food far too slowly. That includes slow cookers, chafing dishes, or even steam cookers.

When your cold leftovers heat up too slowly, they’ll spend too much time at the temperature levels where bacteria can grow very fast.

So, to be safe, stick to quicker and safer methods like stoves, ovens, and microwaves, whichever ones you have in your kitchen.

What Kinds Of Food Should You Never Reheat?

So far, we’ve been discussing the issue of reheating leftovers multiple times. But are there food items that should never be reheated, not even once? As it turns out, yes, there are food items that are unsafe to reheat even just one time.

Simply put, you should never reheat potatoes, mushrooms, breast milk or baby food, seafood, or oily food. Here are the reasons why.


Handful of potatoes

Potatoes are breeding grounds for the type of bacteria that causes botulism. Unfortunately, reheating a potato won’t raise the temperatures enough to kill that kind of bacteria. That’s why it’s unsafe to reheat leftover potatoes unless you want to fall sick.


Reheating mushrooms can also give you a stomach ache because of bacteria, although in an indirect way. The problem with mushrooms is that their proteins can be damaged by bacteria and enzymes. Your stomach won’t be able to handle mushrooms that have been affected that way, resulting in a stomach ache.

If you really want to have those leftover mushrooms, you’ll need to put in the effort to heat it up to at least 158 degrees Fahrenheit.

Breast Milk or Baby Food

Breast milk and baby food can be reheated, don’t get us wrong. It’s just that you should never, ever reheat them in a microwave. This is more of a burn risk than anything else.

As mentioned earlier, microwaves don’t always heat up food evenly. So when you use one to heat up breast milk or baby food, you may mistakenly think that it’s warm to the touch, even though other parts are piping hot. That could lead to your baby suffering from burns on their mouth or tongue. 

So, if you plan on reheating these items for your child, be sure to use any other method that reheats food evenly, like on a stove.


Seafood is always tricky when it comes to food safety, especially when it comes to the issue of reheating leftovers. Here’s the problem: seafood can quickly grow bacteria if it spends any of its time at room temperature or at anywhere between 40-140 degrees.

Worse yet, reheating seafood may not kill all of that bacteria, so it might still pose a risk even if you’ve made it piping hot.

Oily Food

Firstly, you should never reheat oily fried food ever, because they never taste good when you do so. Still, it’s not all about taste; it’s also a matter of safety.

Different kinds of oil get unstable at specific temperatures. So when you put these items in the microwave, you may unknowingly heat them up to a point where the oil generates toxic fumes.

This is yet another kind of leftover that’s best reheated on a stove or in an oven. But again, the unappetizing taste of reheated fried foods might make it not worth the effort.

Bonus Tip: How To Dispose Of Leftovers Without Wasting Them

If you’re reading this article, the chances are high that you kept those leftovers because you wanted to avoid wasting food. 

So now that you know why it’s terrible to reheat them multiple times, what are you going to do with all those leftovers? After all, throwing them in the trash defeats the whole purpose of keeping them in the first place.

Don’t worry! Here’s how you can make the most of those leftovers that are unsafe to eat: you can compost, replant, or turn them into animal feed.


You’ve probably heard that composting is good for the environment. Well, it’s undoubtedly good for reducing food wastage. Simply put, composting means letting that food decompose so that you can use them as fertilizer.

Just because you can’t eat those leftovers doesn’t mean mother nature can’t!


Some types of fruits and vegetables from your leftovers can be used to grow more produce. Do a bit of research and determine which ones you can plant and grow into a little vegetable garden.

Animal Feed

Lastly, you can use leftovers to feed animals around your home. This one is a bit tricky because some animals can’t eat certain food items. Plus, if you live in an urban area, you might attract more of those animals to your home, which your neighbors might not be too keen on.

So, if you’re disposing of your leftovers this way, it’s best to consider the possible outcomes first.

Chef Rooney

I like to cook. It makes me happy, and I know it does the same for others. If you ever want to learn how to make a great dish, just ask!

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