The 4 best ways to reheat leftover fries for extra crispiness

• It's best to reheat fries in a countertop deep fryer or a blazing-hot oven.
• You can also reheat fries in an air fryer or skillet, but you might have to cook them in batches.
• Microwaving fries, which induces steam, is a no-no and should be avoided.

Few eating pleasures surpass grabbing that first french fry from the golden, salt-flecked pile of just-fried goodness and crunching through its crispy shell to a fluffy center.

Of course, that's not always possible, and if you're not motivated to cut and deep-fry your own, you may have to settle for the carryout version. This means at least one of two things: that the fries are already cold and limp by the time they've arrived or that you over-ordered and now have future-soggy fries to contend with.

To help breathe new life into your takeout batons, we've enlisted two British-born masters of the fry — er, chip — to help break down the best ways to reheat them and mimic that just-fried crunch.

Why fries get soggy so fast

From the moment they leave their hot-oil bath, french fries are in a race against moisture and cold, which erode their crispness. The starches inside a potato hydrate when fried and once they start to cool, that moisture sweats out, leading to limp fries.

"The inside of the potato is already moist and steamy and, if the fries were delivered in a takeaway container, they would've been wrapped up and gone sweaty from the steam they've released," says food writer, stylist, and chef Annie Nichols, author of the Potatoes cookbook.

The best type of fries to reheat

The type of fry you get also affects how quickly they get soggy — and how well they reheat. Ed Szymanski, the British-born chef and owner of carryout-only fish-and-chips shop Dame in New York City, opts for fat wedges cut from large russet potatoes to slow the creep of moisture.

Unlike the skinny fast-food ones, large fries are more likely to crisp back up without burning, while maintaining interior fluffiness.

Quick tip: Store leftover fries in an airtight container in the fridge for no more than a couple of days; they get stale quickly.

Method 1: Fry them again

Refrying works best because of its cooking speed. The hot oil warms the fry's surface, while continuing to conduct heat to its interior, creating a sufficiently hot middle and pleasantly crunchy exterior in seconds.

For the best and fastest results, Szymanski swears by a four-quart countertop deep fryer, which retails for around $100. "It's the safest way to fry anything at home," he says. "It has temperature control so you don't have to faff around with a Dutch oven or thermometer and it's small enough to even fit in a New York City kitchen."

1. Prep the fryer. Fill the fryer with canola oil (another bonus of the countertop fryer: you don't have to change the oil every time). Heat it to 375 degrees Fahrenheit and carefully lower in the fries.

2. Cook quickly. They should be crisp and hot in one to two minutes: "Once they're crispy, you're good to go," says Szymanski.

3. Remove immediately. Drain on paper towels and taste.

4. If needed, salt generously. Although your cold, leftover fries were previously seasoned, taste them after you reheat them, no matter the method you choose. "I put hundreds of french fries in my mouth a day; you have to do that at home, even if you're reheating," Szymanski says. "More often than not, I find they need more salt, especially if I'm going to dip them in ketchup."

Best deep fryers

Using your own deep fryer at home can help make leftover fries crispy and delicious. Here are the deep fryers we recommend:

• Best deep fryer overall: Presto Dual Basket Pro Fry Deep Fryer, $59.92 on Walmart
• Best small deep fryer: Presto DualDaddy Electric Deep Fryer, $54.99 on Amazon
• Best deep fryer for easy cleanup: T-fal Oil Filtration Ultimate EZ Clean Deep Fryer, $149 on Amazon
• Best deep fryer for precise cooking: Cuisinart 3.25-Quart Deep Fryer, $79.95 on Williams Sonoma

Method 2: Pop them in a super-hot oven

Absent a countertop deep fryer, our experts prefer a blazing-hot oven and large sheet pan as the most affordable and simple option.

1. Get the oven super hot. Preheat to 450 or 500 degrees Fahrenheit. "Don't be afraid of getting it, like, really hot — so hot that a wave of heat hits you when you open the door," Szymanski says. You shouldn't need to add oil, Nichols adds. Leftover fries already have fat on them, which works as a conductive agent for even heat distribution across the potatoes' surface.

2. Place the fries on a baking sheet. Spread the fries in a single layer on the tray, slide them in, and roast for 3 to 5 minutes, depending on their thickness. "At that temp, you don't even need to turn them," Szymanski adds.

3. Remove immediately. Taste, adding salt if needed, and enjoy.

Quick tip: If your oven has a convection setting, use it. The circulating air will help your fries form a more crisp outer crust.

Method 3: Put them in an air fryer

The air fryer — a small convection oven that mimics deep frying with hot air and a fraction of the oil — is an obvious tool for this task. It will yield super-crispy fries in just a few minutes.

1. Preheat the air fryer. Set the temperature of your air fryer to 375 degrees Fahrenheit.

2. Place the fries in the basket. Leave some space between each fry as you spread them across the bottom of the basket. This will help them heat and crisp evenly. If you have more fries than you have space for in the basket, heat them in batches.

3. Heat the fries. Let the fries heat up in the air-fryer for 3 to 5 minutes, depending on the thickness of the fries.

4. Remove from the air fryer and serve. Once the fries are hot and crispy, they're ready to take out of the air fryer and serve.

Method 4: Pan-fry them

If you don't have a fryer or you're pressed for time, you can also accomplish a second fry on the stovetop, Nichols says.

1. Heat the skillet. Heat a skillet to medium-high.

2. Add oil. You can use 1 to 2 teaspoons of canola or vegetable oil. You may need less oil if your leftover fries still have a sufficient amount of fat on them.

3. Add the fries. Be sure not to overcrowd the pan. You may need to do them in batches.

4. Cook for 3 to 5 minutes. Flip larger fries so they crisp evenly on each side.

Never microwave french fries

The main takeaway for achieving crispy reheated fries is to avoid doing anything to induce steam, meaning — you guessed it — microwaving is out of the question, Szymanski says.

"Microwaves work by heating up water molecules, so if you put fries in, which obviously have water in them, it will make them soggy," he says.

Insider's takeaway

A quick dip in a countertop deep fryer will breathe new life into soggy fries. If you don't have one, roasting them in a hot oven will also do the trick.

You can also throw the fries into a hot skillet on the stove top. Additionally, an air fryer will crisp up a smaller batch of fries in just a few minutes.

But if you have a bigger batch, your best bet is probably a deep fryer or hot oven. According to Szymanski, air fryers are "basically the same thing as putting a little oil on the fries and putting them in a hot convection oven."

Whatever you do, avoid the microwave at all costs, or you'll be left with soggy, limp fries.