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How To Reheat McDonald’s Fries – I Test 10 Methods [Pics]

This article was updated on 18/07/2023 for clarity and to incorporate new insights.

In this article, I reveal the results of my McDonald’s fry reheating experiment (yes, I have actually tested this!). The goal? To find a reheating method that doesn’t leave you with a load of dried-out pieces of cardboard OR a limp, soggy bunch of fries.

I’ll be frank here and say none of the methods I tried were that great, but there were a few that results in decent fries!

The best way to reheat McDonald’s fries is to first microwave them covered with a damp paper towel for 10 seconds. Next, re-crisp the fries by putting them in a 400°F (200°C) air fryer for 20-40 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 night and left them in the fridge for a few hours (16 hours, to be exact).

Around lunch time, I retrieved my (now soggy) fries and set about finding the best way to reheat them. 

I tested reheating them in:

  • The oven: Reliable and decent results.
  • The broiler: Good for crispy fries.
  • The air fryer: Also good for crispy fries.
  • A skillet: A good method.
  • A deep-fryer: Greasy fries.
  • The microwave: Soggy fries.

For each method, I tested various things such as different temperatures or different amounts of oil.

Quick tip

The secret to reheating McDonalds fries is to rehydrate them first and then blast them with dry heat to crisp up the outside. This often means combining methods.

You can rehydrate the fries in the microwave with a damp paper towel, by steaming them in a pan, or in an oven with foil. And then crisp them up in a hot air fryer, under the broiler, or in a hot skillet with oil. My favorite combination was the microwave then air fryer.

Reheating McDonald’s fries in the oven

Time: 4-5 minutes
Rating: 5/10

  1. Preheat the oven to 400°F/200°C (450°F/230°C if you don’t have a convection oven).
  2. Arrange your french fries on a sheet of ridged foil in a baking tray.
  3. Sprinkle a few drops of water over the french fries, then cover them loosely with foil.
  4. Heat the fries for 1-2 minutes.
  5. Uncover the fries and heat them for another 2-3 minutes, or until crisped to your liking.

The ridged foil is a little trick I’ve picked up from all my reheating experiments. It mimics a wire rack and means the fries crisp up evenly from all angles without you having to turn them. You can also use a preheated baking tray.

Covering the fries with foil at first is to rehydrate them, and then you need to uncover them so they can crisp up. 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. 

I also tested heating the fries at 350°F/180°C, but they came out drier because they were in the oven for longer.

Results: 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.

Reheating McDonald’s fries in the microwave

Time: 30 seconds
Rating: 5/10 (straight microwaving) or 7/10 (with a damp paper towel and crisping)

  1. Spread your fries out on a microwave-safe plate so they’re in a single layer.
  2. Optional: cover the fries with a damp paper towel
  3. Microwave the fries on high for 10-30 seconds.
  4. Optional: crisp the fries up under a hot broiler or in a hot air fryer for 30 seconds.

The microwave rehydrates 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 will be too wet to be enjoyed straight out of the microwave if you use a damp paper towel, so skip if if you’re not planning on crisping the fries up afterwards.

If you do want to crisp the fries, you’ll need to work quickly and have the broiler or air fryer already set up. The fries will get hard and cold again quickly if they’re left laying around.

Results: 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, especially when I used the paper towel.

Reheating McDonalds fries in the air fryer

Time: 1 minute
Rating: 6/10 (7/10 with pre-microwaving)

  1. Optional: microwave the fries covered with a damp paper towel for 10 seconds to rehydrate them.
  2. Set the air fryer to 400°F/200°C.
  3. Optional: Spritz your fries lightly with oil.
  4. Arrange the fries in the basket so they’re as spread out as possible.
  5. Heat the fries for 1-2 minutes.

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 tiny bit of oil helps.

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.

Results: 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

Time: 2-3 minutes
Rating: 6/10

  1. Heat a heavy-bottomed pan on a medium-high heat and once hot, add your french fries, making sure they’re in a single layer.
  2. Sprinkle a few drops of water around the edge of the pan and put a lid on for 30 seconds to trap the steam..
  3. Lift the lid off the pan and (optionally) spritz the fries lightly with oil.
  4. Fry the french fries until they’ve crisped up to your liking.

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.

Results: Using the skillet worked out okay for me, but like the other methods, I wasn’t amazed. The fries were slightly better than the oven fries.

Reheating McDonald’s fries by deep-frying

Time: 10-20 seconds (not including oil heating time)
Rating: 3/10

  1. Heat up a saucepan with a few inches of oil (or your deep fat fryer) until the oil reaches 350°F/180°C. 
  2. Add the french fries to the oil a handful at a time.
  3. Heat them for 10-20 seconds before removing them from the oil.
  4. Let the french fries rest on a paper towel for 30 seconds before serving.

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.

Psst… 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. 

Results: 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. The fries were crispy and not too dry, but they had a very oily taste which I didn’t enjoy.

Bonus method: making waffles 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.
Throw a handful of fries into your waffle maker and shut the lid, then leave them to crisp for 4-5 minutes. I like to top the resulting ‘waffle’ with melty cheese but this is optional.

Other things to do with leftover McDonalds’s 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

You can keep leftover McDonald’s fries in the fridge for 1-2 days. 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.

The paper towel soaks up excess moisture and stops the fries 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.

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!):

How To Reheat McDonald’s Fries [Tested Methods]

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.
4.80 from 5 votes
Print Pin Rate
Course: Side Dish
Cuisine: American
Keyword: mcdonald’s fries, reheat mcdonald’s fries
Prep Time: 0 minutes
Cook Time: 3 minutes
Total Time: 3 minutes
Servings: 1 person
Calories: 229kcal


  • 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.



Serving: 100g | Calories: 229kcal

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