Crispy, Oven-Baked Sweet Potato Fries
Sweet potato fries should be the ultimate bar snack—sweet, salty, crispy, and golden. But too often, they’re soft, soggy, or leathery—nothing like the crispy perfection of a good potato fry. Even deep-fried versions at bars rarely hit that shattering crunch. The issue? Sweet potatoes have less starch, more sugar, and more water than russets, making it tough to get a crispy crust before the inside turns limp. The goal here was simple: oven-baked sweet potato fries that are truly crisp, easy to make on a weeknight, and rival the best bar versions—no deep fryer required.
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The Recipe Testing
Achieving restaurant-level crispness without a deep fryer meant testing dozens of techniques. Early attempts—tossing fries in oil then cornstarch, using dry cornstarch alone, or skipping starch entirely—all failed. The results were unevenly browned, dusty, or tough, with a bitter aftertaste. The flavor was okay, but the texture was far from ideal. It was clear that dry starch wasn’t the answer—something more cohesive was needed.
The Secret to Crispy Fries
The breakthrough came from adapting a technique for white potato fries: a cooked cornstarch slurry. Instead of tossing fries in dry starch (which leads to uneven coating), the slurry—made by whisking cornstarch and water, then microwaving until thick—creates a smooth, cohesive layer that clings to each fry. This pre-cooked starch crisps evenly in the oven, mimicking the light crunch of deep-fried fries without the mess.
Equally important was how the fries were placed on the pan. Spraying the baking sheet with cooking spray before adding oil ensured the fat spread into a thin, even film—preventing the fries from steaming or scorching. This created a shallow-frying effect in the oven, critical for consistent crispness.
Fine-Tuning the Texture
Creating a crisp exterior was only half the battle—sweet potatoes cook fast, so the inside can turn mushy before the outside browns. Baking soda solved this by raising the batter’s pH, accelerating the Maillard reaction (the process that creates deep color and flavor) without extending cook time. For an extra layer of crunch, white rice flour was added to the slurry; its coarser texture (compared to all-purpose flour) created a shattering exterior reminiscent of tempura.
Finding the Perfect Cut
Cut size mattered more than expected. Thinner fries (less than 1/2-inch) overcooked before crisping, while thicker ones (more than 1/2-inch) remained gummy inside. The sweet spot? 1/2-inch-thick sticks, cut from halved sweet potatoes to 2 1/2–3 inches long. This balance gave the perfect contrast: golden, crackly outsides and creamy, custardy centers.
The Payoff
The result? Fries that stayed crisp long after coming out of the oven—you could hear the crunch with every bite. Once baked, they were tossed in a homemade seasoned salt (paprika, garlic powder, cayenne) to keep the spices vibrant (adding salt before baking risked bitterness). Paired with a tangy, spicy fry sauce (mayo, ketchup, sriracha, vinegar), these fries delivered on their promise: crispy, flavorful, and worth every minute in the oven.
Recipe Details
Prep Time: 15 minutesCook Time: 35 minutesTotal Time: 50 minutesServes: 3–4
Ingredients
For the Fries
Cooking spray
2 tablespoons (30 ml) neutral oil (e.g., vegetable oil)
3/4 cup (180 ml) water
3 tablespoons cornstarch
3 tablespoons white rice flour
1/2 teaspoon baking soda
2 (12-ounce) sweet potatoes, trimmed, halved crosswise, and cut into 1/2-inch-thick sticks
Seasoned Salt
1 1/2 teaspoons Diamond Crystal kosher salt (use 3/4 teaspoon table salt)
1/2 teaspoon sweet paprika
1/2 teaspoon garlic powder
1/4 teaspoon cayenne
Fry Sauce (Optional)
1/2 cup mayonnaise
1 tablespoon ketchup
1 tablespoon sriracha
2 teaspoons white wine vinegar
1/2 teaspoon garlic powder
Directions
Preheat and prepare: Adjust the oven rack to the lowest position and heat to 425°F (220°C). Spray a rimmed baking sheet with cooking spray, add the oil, and tilt to coat evenly. In a small bowl, mix the seasoned salt ingredients; set aside.
Make the slurry: In a large microwave-safe bowl, whisk the water and cornstarch until no lumps remain. Microwave for 1–3 minutes, stirring every 20 seconds, until thickened to a yogurt-like consistency (add up to 3 tablespoons water if too thick).
Coat the fries: Whisk the rice flour and baking soda into the slurry. Add the sweet potato sticks and toss to coat. Arrange them in a single layer on the baking sheet (one flat side down, spaced apart).
Bake: Bake for 20 minutes until the bottoms brown and release easily. Flip with a thin spatula, rotate the pan, and bake for another 15 minutes until golden brown.
Make the sauce (optional): While the fries bake, whisk together the fry sauce ingredients.
Season and serve: Sprinkle the fries with the seasoned salt and toss to coat. Let cool for 5 minutes on a paper towel–lined platter. Serve with the fry sauce (if using).
Notes
Substitute the homemade seasoned salt with 1 1/2 teaspoons store-bought seasoned salt.
Make-Ahead and Storage
Seasoned salt: Make ahead and store in an airtight container at room temperature for up to 1 month.
Fry sauce: Make ahead and refrigerate for up to 7 days.
Fries: Best eaten immediately, but leftovers can be refrigerated for up to 3 days. Reheat on a baking sheet in the oven until crisp.
Nutrition Facts
Nutrient
Amount per Serving
% Daily Value*
Calories
417
—
Total Fat
24g
31%
Saturated Fat
4g
18%
Cholesterol
12mg
4%
Sodium
1008mg
44%
Total Carbohydrate
46g
17%
Dietary Fiber
6g
21%
Total Sugars
13g
—
Protein
4g
—
Vitamin C
35mg
175%
Calcium
72mg
6%
Iron
2mg
9%
Potassium
861mg
18%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
