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Air Fryer Sweet Potato Fries (Actually Crispy)

CrispyAir Kitchen · Updated October 22, 2026 · Air fryer recipes with exact times & temperatures

Sweet potato fries take 15–18 minutes at 400°F (200°C), flipped twice — but the timing is the least important part of this recipe. Sweet potatoes are sugary and wet, which is why they so often slump: the fixes are a 30-minute cold soak to pull surface starch, a thorough dry, and a teaspoon of cornstarch in the seasoning to give the surface something to crisp with. Manage your expectations honestly — these fries crisp at the edges with tender middles; they will never shatter like a white-potato fry, and that is fine.

Ingredients

• 2 large sweet potatoes (about 1 1/2 lb / 680 g)
• 1 tbsp olive oil
• 1 tsp cornstarch
• 1 tsp smoked paprika
• 1/2 tsp garlic powder
• 1 tsp fine sea salt (finish with half, season with half)

Method

1. Cut the sweet potatoes into 1/4-inch fries, as evenly as you can manage — even fries finish together.
2. Soak in cold water for 30 minutes (or as long as you have), then drain and dry completely between towels. This step is the crispness.
3. Toss the dry fries with the oil, then the cornstarch, paprika, garlic powder and half the salt, until lightly and evenly coated.
4. Preheat the air fryer to 400°F (200°C) for 3 minutes. Spread the fries in a single layer with space — two batches is the honest price of crisp fries.
5. Cook 8 minutes, flip the fries, then cook 7–10 minutes more until the edges are browned and crisp and the middles tender.
6. Salt with the remaining salt and serve immediately with aioli or ketchup.

Tips that actually matter

• Cut them thinner (3/8-inch wedges take 18–22 minutes) if you prefer a sturdier fry; shoestring cuts burn at this heat.
• Frozen sweet potato fries cook at 400°F (200°C) for 13–16 minutes, shaken twice — no soak, no cornstarch needed.
• A pinch of cayenne or cinnamon in the seasoning separates your fries from every other recipe on the internet.

Why this recipe works

Sweet potato flesh is built from sugar and water rather than the dry starch of a russet, so it softens before it can crisp. The soak removes the surface starch that would otherwise turn gummy, thorough drying removes the steam, and the cornstarch donates the crisp jacket the vegetable cannot grow by itself.

Variations to try

The same vegetables, new accents: smoked paprika and cumin for a Spanish lean; curry powder and a squeeze of lime; everything-bagel seasoning after cooking; Parmesan and lemon; or chilli crisp spooned over at the table.

What to serve with it

With burgers and garlic aioli, beside the chicken thighs, or as a snack with a smoked paprika dip.

Storage & reheating

A serve-now food. Leftovers re-crisp at 400°F (200°C) for 3–4 minutes, once.

Frequently asked questions

Why are my sweet potato fries soggy?

Crowding, skipping the soak, or fries that went in damp. Sweet potatoes carry sugar and water — space and drying are non-negotiable.

Is the cornstarch essential?

It is the closest thing to essential in this recipe — it builds the thin, crisp jacket sweet potato flesh cannot make alone.

Can I make these without oil?

You can, but the fries will be drier and paler. One tablespoon across four servings is a small price for fries that actually work.

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