Sweet Potato Fries

February 20, 2020
3 Ratings
Photo by Rocky Luten. Prop Stylist: Megan Hedgpeth. Food Stylist: Anna Billingskog.
  • Prep time 30 minutes
  • Cook time 30 minutes
  • Serves 2
Author Notes

I don’t think I’ve ever enjoyed an oven-baked sweet potato fry. Despite their—and our—best efforts, potatoes cut thinly, tossed in oil, and roasted in a screaming-hot oven, often emerge dry and leathery, hard but not crisp. And yes, there’s the par-boiled then hard-roasted fries, but those, at their best, taste like, well, roasted sweet potatoes.

So I retraced. For a fry to be truly called a “fry,” shouldn’t we be frying? But, sure enough, there’s a reason sweet potato fries are often made in the oven: Dropping sweet potatoes—which contain more sugar, more water, and less starch than regular potatoes—in hot oil will yield fries that burn before ever becoming crisp. Bear with me as we talk fry-ence.

I turned to food science–wizard (and Serious Eats and New York Times contributor) Kenji J. López-Alt’s fry guide for answers: He adds vinegar to his fry blanching water. Vinegar, he says, slows the breakdown of pectin present in potatoes. So how about we slow it—and the resulting Maillard reaction—even more? I added double the amount of vinegar he recommends to the blanching water, along with salt (why not season the fry’s interior while we’re here?). Tossing the blanched fries in a cornstarch slurry ups the starch that sweet potatoes naturally lack, creating a barrier that’s eager to crisp.

The result? Sweet potato fries that are tender, not dry nor hollow, and so very crispy. There was not a leathery, chewy, nor hard one in the batch. And, the fries actually tasted of sweet potato—not fry oil—thanks to that seasoned blanching water. Hit these with more seasoning if you want—like cinnamon sugar, kale-pecorino dust, or zab-zab. But they really are so good on their own—you might not even need ketchup. —Coral Lee

What You'll Need
  • 2 tablespoons cornstarch
  • 1 medium sweet potato (about 1/2 pound), unpeeled, cut to 1/4-inch matchsticks
  • 1 tablespoon white vinegar
  • 3/4 teaspoon kosher salt, plus more for finishing
  • 4 cups frying oil, such as canola, vegetable, or peanut
  1. Whisk the cornstarch with 2 tablespoons of water in a large mixing bowl until smooth. Set aside.
  2. Combine the potato, vinegar, ¾ teaspoon salt, and 2 cups of water in a small saucepan. Bring to a boil over high heat, then reduce the heat and simmer for 10 minutes, or until tender but not falling apart. Using a slotted spoon or spider, lift the potatoes out of the water, tapping a few times to drip dry, then transfer to the bowl of cornstarch slurry. Toss to coat well, taking care not to break our (strong, but tender!) fries.
  3. Pour the oil into a medium stock pot fitted with a frying thermometer, and set over high heat. Also heat the oven to 200°F—this is where we’ll be keeping our fries warm.
  4. Once the oil reaches 325°F, drop in a third of the fries. Fry for 8 minutes at 325°F, agitating with a pair of tongs or cooking chopsticks to prevent large clumps from forming, and dropping or raising the heat as needed. Lift fries out with the same slotted spoon or spider, and transfer to a towel-lined baking sheet. Season with salt, and keep warm in the oven as you repeat with the remaining two batches.
  5. If you don’t have a thermometer, you can test the oil by dropping in a fry—if and when the oil bubbles fiercely, like froth, around the fry, you’re good to go. I found that to keep the oil at 325°F required maintaining high heat for the first 5 to 6 minutes of frying, then dropping the heat to medium-low for the last 1 to 2 minutes of frying.

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  • Emily Grace Kubal
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2 Reviews

Emily G. April 27, 2020
Love the recipe! Finally sweet potato fries that taste good.

Only change I made is the cooking time when blanching. The recipe says to bring the water to a boil with the potatoes already in the water. If you leave the fries for the entire ten minutes as called for, they are overcooked. Instead, I found the fries are tender by the time the water starts to boil.

I also made a seasoning salt with paprika, chili powder, garlic powder, and of course, kosher salt. Toss these babies in the spice mix when they come out of the oil and keep them in a low temperature oven until the rest are done. It helps to have a rack on top of a baking sheet to keep them extra crispy!
Bella B. February 22, 2020
This looks just delish!

xoxoBella |