Much of what goes into making the perfect french fries has to do with ensuring that the center of the fries are fully cooked before the outsides get too brown. The way we achieve that is by cooking the fries twice.
Frying your fries twice might sound like a lot of work. But if you want them light and crispy, that's what you've got to do. Otherwise, they'll either be crispy but undercooked in the middle, or just plain greasy and limp. We'll describe the twice-frying technique below, but first let's talk about what kind of potatoes to use.
High starch potatoes like Idaho potatoes (also called Russet potatoes) are best because they're denser and have the least amount of moisture in them. Waxy potatoes will actually hollow out when you fry them, because they have more water in them and the water evaporates while they cook.
As soon as you cut the fries, you're going to transfer them to a bowl of cold water with a tablespoon of lemon juice added. Cut potatoes will start to discolor if they're exposed to oxygen for too long — even if they're in water. (There's oxygen in water, after all.) But a little bit of acid in the water helps keep the potatoes nice and white.
- Peel the potatoes, and remove any eyes.
- Square off the potato with your knife and slice it into ¼-inch slabs. Now cut each slab into ¼-inch strips. The fries should be about 3 inches long. Transfer them to the cold water as you go.
- When the fries are cut, rinse them under cold water into the bowl until the water turns clear. The idea is to rinse off any excess starch.
- Add another tablespoon of lemon juice, and then a few cups of ice — enough to chill the water thoroughly. Transfer to the fridge for about 30 minutes. We chill the potatoes because we want to keep the outside of the french fries from getting too brown too quickly. Chilling them helps the inside of the french fries cook all the way through before the outsides get too dark.
- Now would be a good time to talk about oil. If you want the short version of the story, here you go: Refined peanut oil is the best oil to use for making french fries. You can also use canola or safflower oil. If you want the long version of the story, see Why Are Restaurant French Fries So Crispy?
- Next we come to the the actual cooking. We want to fry the french fries twice: once at a lower temperature, so that the inside of the potato gets cooked; and then a second time at a higher temperature, which is when the fries turn golden brown and crispy.
- You can use a home deep-fryer, or just heat the oil in a Dutch oven using a candy or frying thermometer to monitor the oil's temperature. I use the kind that clips onto the edge of the pot so that it doesn't slide around.
- Drain the fries from the icewater bath they've been soaking in and dry them in a clean kitchen towel. Adding wet potatoes to the hot oil could cause it to spatter. You're also going to want to set up a couple of sheet pans lined with thick paper nearby. Brown paper grocery bags work great for this.
- First, heat the oil over medium-low heat to 325°F. Cook the potatoes in the oil for 6 to 8 minutes, or until they're soft and they've taken on a slightly golden color.
- Remove the fries from the oil using a wire mesh skimmer (sometimes called a spider spoon) and transfer them to the paper-lined pans to drain. You can refrigerate them again until you're ready to use them, or at the very least let them stand at room temperature for 15 minutes. Remember to turn off the heat under the oil during this time.
- Now heat the oil to 375°F. Return the fries to the oil and cook for another 2 to 3 minutes or until the fries are golden brown and crispy. Drain on clean paper, then salt generously and serve right away.