If you’ve recently been defeated by your McDonald’s fries, you may be wondering if you can keep them and reheat them later.
In this article, I reveal the results of my McDonald’s fry reheating experiment (yes, I have actually tested this!).
The goal? To find the best reheating method that doesn’t leave you with a load of dried-out pieces of cardboard OR a limp, soggy bunch of fries.
In a rush? Here’s the short answer.
The best way to reheat McDonald’s fries is to first microwave them covered with a damp paper towel for 20 seconds. Next, re-crisp the fries by putting them in a 350°F (180°C) air fryer for 20-30 seconds. Alternatively, you can use the broiler or a dry skillet to add the crisp back to the fries.
A note on my experiment
I bulk ordered fries from my local McDonald’s one morning and left them in the fridge for a few hours (12 hours, to be exact).
Around dinner time, I retrieved my (now soggy) fries and set about finding the best way to reheat them.
- Reheating them in the oven
- Reheating them under the broiler
- Reheating them in the air fryer
- Reheating them in a skillet
- Reheating them by deep-frying
- Reheating them in the microwave
I tested various things for each method, such as different temperatures in the oven or whether you need to add extra oil in the skillet.
So, how did the experiment go?
I’ll be frank here and say none of the methods I tried were that great.
The fries had lost their signature taste, and nothing I did brought it back. The texture was also really hard to get right. The fries were either slightly dry or slightly soggy.
But if you’re dead set on reheating your Mcdonalds french fries, the secret is to re-moisturize them first and then blast them with dry heat to crisp up the outside.
There are a few ways to do this, which I explain below.
The best way to reheat McDonald’s fries
As I mentioned above, the key to successfully reheating McDonald’s fries is to first remoisturize them and then crisp them up.
There are several different methods you can use to re-moisturize the fries, including:
- Microwaving the fries with a damp paper towel over them.
- Sprinkling the fries with water, then covering them with foil in the oven.
- Heating the fries in a pan with a few drops of water and a lid.
Crisping techniques include:
- Heating the fries in an air fryer.
- Heating the fries under the broiler.
- Heating the fries uncovered in the oven.
- Frying the fries in a pan with some oil.
How you combine these techniques is up to you, but here are my suggestions:
- Remoisturize: microwave the fries with a damp paper towel over them.
- Crisp: heating the fries in an air fryer or broiler.
- Remoisturize: sprinkle the fries with water, then cover them with foil in the oven.
- Crisp: open the foil and heat the fries uncovered in the oven or use the broiler.
- Remoisturize: heating the fries in a pan with a few drops of water and a lid.
- Crisp: fry the fries in a dry pan with a spritz of oil.
My top recommendation is the microwave and then the air fryer (or broiler if you don’t have an air fryer). The microwave steams the french fries, and the air fryer is powerful enough to give them their crunch back.
Reheating McDonald’s french fries in the oven
To reheat McDonald’s french fries in the oven, preheat it to 400°F (200°C) while arranging the fries in a single layer on a baking tray. Sprinkle a few drops of water over the fries and cover them with foil. Heat the covered fries for 2-3 minutes before uncovering them for the last 1-2 minutes.
I used a toaster oven in my experiment. Larger convection ovens will work similarly.
If your oven isn’t a convection oven, I recommend using a higher temperature (450°F (230°C).
How to reheat McDonald’s french fries in the oven:
- Preheat the oven to 400°F/200°C (450°F/230°C if you don’t have a convection oven).
- Arrange your french fries on a baking tray (or on a sheet of ridged foil as in the picture above).
- Sprinkle a few drops of water over the french fries, then cover them with foil.
- Heat the fries for 2-3 minutes.
- Uncover the fries and spritz them lightly with oil (shake them about if you’re just using a baking tray).
- Heat the fries for another 1-2 minutes until crisped to your liking.
Covering the fries with foil helps to keep them moist. Uncovering the fries near the end allows their skin to crisp up (but you may not get the crispiest of skins).
Go really easy on the water. A few drops is more than enough.
Too much water, and you’ll never be able to crisp the fries up.
If crispy skin is more important to you than a moist inside, skip the foil and the water and just heat the fries uncovered for 3-5 minutes.
The longer you heat the fries, the crispier (and drier) they’ll become.
The ridged foil is a little trick I’ve picked up. It mimics a wire rack and means the fries crisp up evenly from all angles and means you don’t have to open the oven to turn them.
I also tested heating the fries at 350°F (180°C), but they came out drier because they were in the oven for longer.
I prefer slightly moist fries, so I wasn’t a fan of the straight oven. It dried the fries out too much, and they were hard work to eat.
The foil method improved things for me, but it still wasn’t amazing.
The oven is probably the best method if you have lots of fries to reheat because you avoid having to do them in batches.
Reheating McDonald’s fries in the microwave
Spread the McDonalds fries out on a microwave-safe plate and heat them for 20-30 seconds. The result will be slightly soggy, but edible fries. For better results, cover the fries with a damp paper towel in the microwave and then crisp them up under the broiler or in the air fryer afterwards.
Rating: 5/10 (straight microwaving) 7/10 (with a damp paper towel and crisping)
The microwave is best for people whose main priority is keeping the french fries soft.
How to reheat Mcdonald french fries in the microwave:
- Spread your fries out on a microwave-safe plate so they’re in a single layer.
- Microwave the fries on high for 20-30 seconds.
- Let the fries rest for a few seconds before serving.
Optional (but recommended) steps:
- Cover your fries with a damp paper towel before putting them in the microwave.
- Crisp the fries up after microwaving them by putting them under the broiler or in the air fryer for 30-60 seconds. You can also use a chef’s torch if you have one (I tried it, and it was pretty tasty, the flame gave the fries a charred flavor).
The microwave re-moisturizes the french fries and keeps the inside filling soft. However, the outside won’t crisp up.
Swings and roundabouts, eh?
The damp paper towel effectively steams the fries and produces the moistest but soggiest results.
The french fries were too wet to be enjoyed straight out of the microwave, so only use this method if you’re able to crisp the fries up afterwards.
I surprised myself and didn’t mind the microwaved fries. They didn’t have much (any) crunch, but it felt like I was actually eating potato rather than a dried-out shell.
The filling of the french fry was still soft and moist.
Even more so when I used the damp paper towel, and because the fries were so moist, the subsequent crisping didn’t dry them out completely (although they weren’t the crispiest of fries).
Reheating Mcdonalds fries in the air fryer
To reheat Mcdonald’s fries in the air fryer, set it to 400°F (200°C) and spread the fries out in the basket. Spritz the fries lightly with oil and heat them for 1-2 minutes. For a moister fry, cover them in a damp paper towel and microwave the fries for 20 seconds. Crisp them in the air fryer.
Rating: 6/10 (7/10 with pre-microwaving)
The air fryer produces the crispiest fries but can be drying.
How to heat Mcdonalds fries in the air fryer:
- Set the air fryer to 400°F (200°C).
- Spritz your fries lightly with oil (optional).
- Arrange the fries in the basket so they’re as spread out as possible.
- Heat the fries for 1-2 minutes.
- Let the fried rest for 30 seconds before serving.
The oil step is optional. The fries will already have some residual oil on them from their first cooking, which will help them crisp up in the air fryer.
But if you want to revive the fries’ ‘just-fried’ taste, a bit of oil helps.
Just make sure the coating is very light; otherwise, the fries will end up saturated.
Don’t overcrowd the air fryer too much, or the fries in the middle won’t crisp up properly.
If you have lots of fries to reheat, do it in batches.
The air fryer fries were tasty and crispy, but (as expected) they were on the dry side, although less so than the oven fries.
You can solve the dryness issue by microwaving the fries before heating them in the air fryer.
Reheating McDonald’s fries in the skillet
To reheat McDonald’s fries in the skillet, heat a pan on medium-high heat and spread the fries out in a single layer. Sprinkle a few drops of water over the fries and put a lid on the pan. Heat for 30 seconds before uncovering. Spritz some oil into the pan and fry the fries until crispy.
The water helps keep the fries soft and moist, while the frying crisps the outside.
How to reheat McDonald’s fries in the skillet:
- Heat a heavy-bottomed pan on a medium-high heat.
- Add your french fries, making sure they’re in a single layer.
- Sprinkle a few drops of water over the french fries.
- Put a lid on the pan and steam the fries for 30 seconds.
- Lift the lid off the pan.
- Spritz the fries lightly with oil. (optional)
- Fry the french fries until they’ve crisped up to your liking.
- Let the french fries rest for 30 seconds before serving.
Steps 3-5 help to add some moisture back into the fries and keep the inside soft.
If you’re not that bothered about a soft inside and prefer a crunchy outer layer, you can skip these steps.
Go easy on the oil if you decide to add any because the fries can easily become over-saturated. I advise adding a spritz because it adds some extra flavor to the french fries.
Using the skillet worked out okay for me, but like the other methods, I wasn’t amazed. The fries were on par with the oven fries.
You do need to be really careful not to add too much water to the pan, or the fries will get too soggy. A couple of drops is all you need.
Reheating McDonald’s french fries by deep-frying
To reheat your Mcdonald’s french fries in a deep fryer, heat the oil to 350°F (180°C) and submerge the fries for 10-20 seconds. Work in batches so you don’t overwhelm the fryer. Be aware that any salt on your fries will lower the oil’s smoke point and accelerate degradation.
This is a highly involved method with average results. I don’t recommend it.
How to reheat Mcdonald’s french fries in the deep fryer:
- Heat up a saucepan full of oil (or your deep fat fryer) until the oil reaches 350°F (180°C).
- Add the french fries to the oil a handful at a time.
- Heat them for 10-20 seconds before removing them from the oil.
- Let the french fries rest on a paper towel for a minute before serving.
Salt and oil don’t mix, which is unfortunate because Mcdonald’s french fries are pre-salted unless you specifically ask for no salt.
Putting salt into your oil accelerates the rate of oil degradation and means you’ll have to throw it away sooner.
The oil temperature is critical here, so I don’t suggest winging it. Use a dedicated deep fat fryer or an accurate cooking thermometer.
If the oil’s too cold, the fries will soak it all up and become soggy.
If it’s too hot, the fries will burn.
Honestly, I don’t recommend this method.
It was a lot of effort to heat the oil up to the right temperature (although less so if you own a deep fat fryer), and the results were mediocre at best. Plus, you have the issue of the salt ruining your oil.
The fries were crispy and not too dry, but they had a very oily taste which I didn’t enjoy.
Too much effort and not enough reward.
Use a waffle maker and make waffle fries
If you don’t fancy eating the french fries as they are, or you think you’ve left them a bit too long to revive them, you can always reinvent them.
Nothing goes to waste in my house – as long as the food is safe to eat, I will think of a way to jazz it up.
The best one I’ve tried with fries is to make them into a crispy, cheesy waffle.
How to make a McDonald’s french fry waffle:
- Preheat your waffle maker according to the instructions.
- Put your fries in the waffle maker and shut the lid firmly.
- Leave the fries to crisp up for 8-10 minutes.
- Open the waffle lid and top the fries with cheese. (optional)
- Close the lid for 2-3 seconds to melt the cheese.
- Serve the waffle with your choice of sauce.
If you don’t have a waffle maker, you can get the same crispy effect with a George Foreman grill or toastie maker, but the fries might not stick together as well.
Other things to do with leftover french fries
If a french fry waffle doesn’t float your boat, here are a few other ideas for using up leftover Mcdonald’s french fries:
- Chop up your leftover fries and turn them into hash browns or tater tots.
- Add the fries to your breakfast burritos.
- Add the fries to an omelet or frittata.
- Make poutine or some other loaded fries dish (bacon, cheese, and jalapenos is my favorite combination, made even better when you fry the fries in the bacon grease for a few seconds).
How to store leftover McDonald’s fries
Keep leftover McDonald’s fries in the fridge. Once the fries have cooled to room temperature, put them in an airtight container lined with a paper towel. Keep the fries to a single layer, separating each layer with more paper towel. Use the fries as soon as possible, and always within 4 days.
The paper towel soaks up excess moisture and stops the fried from becoming too soggy.
Always wait until the fries are at room temperature to store them. Otherwise, condensation will build up in the container and render your fries soggy.
French fries, especially fast-food french fries like McDonald’s or five guys, don’t store particularly well.
It’s best to eat them on the same day or at the very latest the next day.
Every day they’re stored, the quality will decrease, and it will be even harder to reheat them to their former glory.
Have you got other McDonald’s food that you want to reheat?
Check out my other reheating experiments (Psst, they reheat a lot better than fries!):
- Exactly How To Reheat A Big Mac [I Test 4 Methods]
- The Best Way To Reheat McNuggets [I Test 6 Methods]
The BEST Way To Reheat McDonald’s Fries
- 1 portion McDonald's fries
- 1 spritz oil optional
- Spread your fries out on a microwave-safe plate so they’re in a single layer.
- Cover the fries with a damp paper towel.This creates steam in the microwave and rehydrates the fries.
- Microwave the fries on high for 20-30 seconds.
- Transfer the fries to a preheated air fryer (350°F/180°C) for 20-30 seconds. This 're-crisps' the fries.
- Alternatively, you can crisp the fires in a broiler instead of an air fryer.