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Do you enjoy being lied to? I certainly don't. Yet nearly every time I eat roasted potatoes, I feel like I've been betrayed. They come to the table all nicely browned and craggy, but they inevitably have soft, papery skins that don't offer any real contrast with the creamy flesh below. It's like, hey potatoes! What'd I ever do to you? Why do you gotta lie to me like that?
[**grumblegrumble** stupid lying potatoes **grr**]
What's even worse are the recipes that promise crispness, but produce potatoes that are crisp for all of 8 seconds after they come out of the oven, only to soften on their way to the table.
When I say crispy potatoes, I want potatoes crunchier than the best of french fries; a thick, craggy, crunchy crust that stays crunchy even after it's made its way through a couple circuits around the table.
Luckily, the process isn't as hard as it sounds. I outlined it once a couple years ago using chunky russet potatoes. This year, we're going with creamy new potatoes and adding a lemon and herb blend to the mix.
New potatoes offer some challenges that russet potatoes don't. Namely, they're less starchy, which makes it even harder to build up a significant crust.
There are two ways in which crusts can go badly wrong. Papery crusts that soften quickly occur when the crusty layer isn't thick enough. Tossing raw potatoes in oil and throwing them in the oven is a surefire way to get yourself papery crusts.
Leathery or tough crusts, on the other hand, are caused when the crust layer becomes too dry. As moisture leaves the potatoes, cell walls get packed closer and closer together, turning the crust dense and tough.
So how do you avoid these two problems? Let's take a look.
Problem: Papery Crust
Solution: Par-boil the potatoes in acidic water.
Papery crusts occur when the layer of gelatinized starches that crisp up on the exterior of the potato isn't thick enough. As the potato comes out of the oven and sits, steam from its core penetrates the crust, softening it from the inside out.
Par-boiling the potatoes will help build up this layer of starch, while adding just a touch of vinegar to the water will allow the starch to gelatinize while keeping the potatoes relatively firm and intact.* This gives you potatoes that are crisp on the outside, but still hold their shape with a creamy, not gluey, core.
*Pectin, the glue that holds vegetable cells together, doesn't break down very readily in acidic environments. It's a trick I learned while researching french fries a few years ago.
Want to get those potatoes even crispier? After par-boiling them, I toss the potatoes in the pot with oil, bashing them around a bit until their exteriors are coated in a film of bashed up potato bits. With new potatoes, this step is particularly important—it allows you to crisp up not just the cut surfaces, but the skins as well.
Problem 2: Leathery Crust
Solution: Use plenty of fat.
You may have heard in the past that frying foods at high temperatures will limit the amount of fat they absorb. This is a long-perpetuated myth with little basis in reality. In fact, the opposite is actually the case. The reason why food fried at high temperatures tastes so good is because those high temperatures drive out more moisture, which gets replaced by oil. That oil not only adds flavor to the food, but it also keeps the crust from collapsing on itself and becoming dense.
So, as a general rule of thumb, the crispier your food, the more oil it's absorbed. Hey, I never said these potatoes were healthy per se.
While we aren't deep frying these potatoes, we still want them to have plenty of access to oil as they cook so that as moisture leaves the crust, there's something there to take its place. Not only do I toss the potatoes with oil before roasting, but I make sure that the sheet pans I roast them on are well-oiled as well.
Starting the potatoes cut-side-down and blasting them with high heat helps ensure even browning all around.
You can keep things simple and go with just salt and pepper if you'd like, but for some added flavor, I like to toss some shallots in with the potatoes just before they're done. They brown and crisp in the oven rapidly, so make sure to keep an eye on them.
The goal is "artfully charred," not burnt.
Finally, I toss the cooked potatoes with some extra-virgin olive oil, chopped herbs, lemon zest, and garlic as soon as they come out of the oven.
The residual heat of the potatoes will volatilize the aromatics in the herbs and lemon zest. If your nose doesn't thank you at that point, then you need to sit it down and have a serious talk with it about its manners, or lack thereof.
More Potato Recipes!
- Crispy Potatoes with Garlic-Parmesan Butter
- Crispy Smashed Potatoes
- Ultra-Crispy Roast Potatoes
- Ultra-Fluffy Mashed Potatoes
About the author: J. Kenji Lopez-Alt is the Chief Creative Officer of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.