I’ve made my fair share of “almost crispy” potatoes—golden on the outside, a little too soft in the middle, and never quite restaurant-level perfect. I always assumed I just wasn’t using enough oil. But after testing a little tip I found from a chef online, I learned the real secret ingredient was hiding in my pantry all along: cornstarch.
Yes, cornstarch—the same thing I use to thicken gravy. Turns out, it’s the not-so-secret weapon for perfectly crisp, crunchy potatoes that stay that way even after cooling.
Why Cornstarch Works So Well
The science behind it is surprisingly simple. When you toss potatoes in oil alone, they crisp up at first—but that texture fades fast once the steam hits. Cornstarch, on the other hand, creates a super-thin coating that locks in moisture and crisps the surface evenly. It’s like giving your potatoes their own little armor of crunch.
Chefs use this same trick on everything from Korean fried chicken to tofu—it’s just finally getting the recognition it deserves for roasted potatoes.
How I Do It
Here’s how I’ve been making my potatoes ever since I discovered this game-changer:
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Cut your potatoes evenly. Cubes, wedges, or fries—just make sure they’re similar in size.
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Soak them in cold water for 20 minutes. This removes extra starch that can make them gummy.
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Dry them really well. Moisture is the enemy of crispiness.
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Toss with oil and cornstarch. About 1 tablespoon of cornstarch per pound of potatoes is plenty. Add your seasonings—salt, pepper, garlic powder, paprika, whatever you love.
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Roast at 425°F. Give them space on the pan so they crisp instead of steam. Flip halfway through, and get ready for potato perfection.
The First Time I Tried It
The first batch I made with cornstarch honestly shocked me. They came out shatteringly crisp on the outside and fluffy inside—the kind of texture that makes you forget to grab ketchup. My husband walked by, stole one, and immediately said, “What did you do differently?” That’s when I knew it wasn’t a fluke.
Now, I make them at least once a week—breakfast potatoes, dinner sides, even air-fried versions. It works every time.
A Few Extra Tips
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Don’t skip the drying step. Wet potatoes make steam, not crunch.
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Use parchment paper or a well-oiled pan. Cornstarch can stick if the surface isn’t slick enough.
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Try arrowroot powder if you’re out of cornstarch. It works the same way.
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Want extra flavor? Toss with grated Parmesan in the last few minutes of roasting—it sticks perfectly to the crispy coating.
Why I’ll Never Go Back
Now that I know the trick, I’ll never rely on oil alone again. Cornstarch gives me that perfect crunch every single time—no deep frying, no gimmicks. Just one simple pantry staple and a little kitchen magic.
So next time you make potatoes, skip the guesswork and grab the cornstarch. Trust me, once you hear that first crispy bite, you’ll never make them any other way.