We know, it's so rare that you ever have leftover French fries. Who would want to leave any of these crispy, salty bites of goodness on the plate? But it happens, so we've got some tips on the best way to reheat fries so that they are almost as tasty the next day.
First off, we should note that to best reheat fries, you want to use restaurant-quality take-out fries, not fast food. Nothing against fast food fries, but they're not going to reheat as well. If you really want to reheat fast-food fries, we suggest repurposing them as part of another dish. Day-old fries from fast food joints will never regain their crispiness even if you put them in the deep fryer.
Step Away from the Microwave
Grab your leftover fries out of the refrigerator. Now, walk away from the microwave. No, really, it's not worth it. You'll get limp, soggy fries and nobody wants that.
Microwaving cold fries is basically steaming them. Because the microwave works by heating the inside of the fry first, the moisture inside each fry turns to steam, which makes the outside of the fry lose its crispness. Your goal is to gently reheat the inside while re-crisping the outside. For that, you need the stove as the perfect reheating tool.
The Stove is the Best Way to Reheat Fries
A cast-iron skillet on the stovetop heated over medium-high heat is the best way to reheat almost any fried food. Make sure you use a large enough pan; if you overcrowd the pan, you get a steam effect from the moisture as it heats up. If you have a lot of fries, reheat them in batches.
Add a little oil to the pan and let it heat until the oil shimmers; you'll want to use cooking oil like vegetable oil with a high smoke point. You can reheat the fries without the extra oil (they should retain some of the original oil in which they were fried), but using a bit more will help the potatoes crisp up again.
When the pan is hot, add the fries in a single layer. Cook for a minute, then flip the fries. Cook each side for 30 seconds to a minute, or until they are nice and crisp. Place the hot fries on a paper towel to drain the excess oil, then add a little bit of extra salt, other seasonings, or Parmesan cheese and prepare to enjoy.
Second Choice: The Oven
It takes a little bit longer, but the oven method works to reheat fries almost as well as a skillet on the stove. Preheat your oven to between 400-450ºF and pop your baking sheet into the oven to preheat as well.
Once the oven is hot, spread the fries out on the baking sheet in a single layer. They'll need to spend at least four or five minutes in the oven until they're a nice golden brown, but keep an eye on them because they might need a few minutes more for if you've got a big pile of fries.
If you're hoping to reheat French fries at work where you don't have a full kitchen, know that toaster ovens work just as well as their bigger counterparts. Remember not to crowd the fries when you heat them; if you can heat the little toaster baking sheet for a minute before placing the fries on it, all the better.
Repurpose Those Fries
Leftover fries also work really well as the basis for other dishes. You can chop them up and use them in a breakfast hash or in a frittata. Or you might repurpose them as hashbrowns or tater tots.
Or you could use them as the foundation for two of the best potato dishes in the world: Disco Fries and Poutine. Variations on the same idea coming to us from New Jersey and Canada respectively, both are basically fries topped with cheese and gravy. (If you're going to reheat fast-food fries, this is how to do it, because almost anything tastes better covered with gravy and cheese.)
Plain or with toppings, with a little patience and attention, leftover fries can be just as good the next day.