The secret to reheating french fries

French fries have long been considered to be a kind of Jekyll and Hyde food — they are absolutely delicious when they're fresh out of the fryer, but after they've cooled off a bit, they lose quite a bit of their appeal, and any leftover french fries tend to be notoriously difficult to revive.

But wait, don't abandon those fries on the plate! While the microwave is definitely not the way to go if you want your fries to be edible the day after, there are several methods of reheating leftover fries that will render them crunchy and delicious once more.

​Why microwaving fries doesn't work so well

One experience with microwave-warmed day-old fries is really all you need to learn that the experiment doesn't bear repeating as it turns them into a soggy mess. Why would this be, when the microwave does such a great job of reheating other types of leftovers? 

There are actually several reasons. For one thing, a microwave heats from the inside out, so your fries won't get crispy without being overcooked. For another, the heat can be uneven, so some fries may burn while others stay limp. And if you're reheating them in any kind of container like, say, a cardboard takeout box, that container will trap the moisture inside and basically steam-cook your fries, which is no way to treat a poor potato.

How to re-fry french fries

According to The Kitchn, the best way to reheat fries involves frying them a second time. You do not need a deep fryer similar to the one that birthed your fries in the first place, and, in fact, you probably wouldn't want to re-immerse them in such a huge quantity of oil, anyway. 

What you are going to need, however, is a large skillet (cast iron is always a good choice) and just a bit of oil — two teaspoons for every cup of fries. First, you'll heat the skillet over medium heat, then you add the oil and heat it until it's shimmering. Add a single layer of fries, and cook them for one minute before flipping them with a spatula. Let them fry for about 30 seconds longer, then salt them and eat them while they're hot. 

Be sure not to overcrowd the pan with fries, though — if you're reheating a lot of fries, do so in small batches. If you have too many fries in too small a pan, they may end up steamed instead of sauteed, and won't be much better than if you'd used the microwave after all.

​Reheating fries in the oven

If you're reheating a large amount of fries, or else you'd just prefer a less messy way than cooking them on the stovetop, using your oven will also work quite well. Wonder How To Food Hacks advises that, in order to ensure crispness, it is very important that you actually take the time to preheat the oven to 450 degrees, and that you also use a sturdy baking sheet. That cast-iron skillet will also work, as long as all your fries fit in without crowding.

You can oil your baking sheet, although it's not entirely necessary that you do so, but no matter what, you should put the sheet or pan in the oven, without fries, while the oven is doing its preheating thing. Once it's reached the proper temperature, take the hot pan out (using a potholder or oven mitt!) and spread a single layer of fries on top. 

Next, return it to the hot oven, and check the fries every few minutes until they've reached the desired degree of crispiness. A single serving of fries should take just a few minutes, but it might take up to 10 minutes if you're reheating a large batch. Once the fries are done, remove them from the oven and season to taste.

Other things to do with leftover fries

If you want to get creative, you can try a tip from the Salvage Sister and Mister blog and put them in your waffle iron to create some jumbo-sized waffle fries. You can also chop them up and use them to make hash browns or home fries, or you could use them in a breakfast burrito, a skillet or a frittata, or even in a soup. Perhaps you could try making them into poutine, too.

While reheated and/or repurposed fries are never going to be quite as wonderful the second time around, isn't that also true of so many things in life? Just seize the day, seize the salt shaker, and scarf down those almost-as-good fries before they cool down again.