Soaking the cut raw potatoes in water removes surface starch, which yields crispier fries and prevents them from clumping together as they cook. Make sure to dry them thoroughly so that they don't cause the hot oil to spatter when you add them to the pot.
- 1 1/2 pounds russet potatoes, unpeeled, cut into 1/4-inch-thick sticks
- Vegetable oil (for frying; about 6 cups)
Place potatoes in a medium bowl; add cold water to cover and chill overnight. Drain; cover with cold water and let soak 1 hour longer.
Fit a large pot with thermometer; pour in oil to measure 3”. Heat over medium-high heat until thermometer registers 375°.
Drain potatoes and gently pat dry. Working in batches and returning oil to 375° between batches, fry until golden and crisp, about 5 minutes. Using a spider or slotted spoon, transfer fries to a paper towel–lined baking sheet; season with salt and Old Bay.