Cut the Potatoes: Wash and peel (optional) the russet potatoes. Slice into even ¼-inch sticks using a sharp knife or mandoline. Uniform size helps the fries cook evenly.
Soak the Potatoes: Place the cut fries into a large bowl of cold water. Soak for at least 30 minutes, or up to 2 hours, to remove excess starch. This prevents sticking and helps the fries crisp up.
Dry Thoroughly: Drain the potatoes and spread them out on a clean kitchen towel or paper towels. Pat completely dry. Moisture left on the potatoes will cause oil splatter and soggy fries.
Heat Oil for the First Fry: Pour enough vegetable oil into a deep, heavy-bottomed pot or Dutch oven to reach about 2 inches in depth (about 4 to 6 cups, depending on pot size). Heat the oil to 350°F, checking with a deep-fry thermometer.
First Fry (Blanching): Working in small batches (about a handful at a time), add the potatoes carefully to the hot oil. Fry for 3-4 minutes, or until the fries are softened but not browned. Remove with a slotted spoon or spider strainer and drain on paper towels or a wire rack. Allow the oil to return to 350°F before frying the next batch.
Rest the Fries: Let the blanched fries rest at room temperature for at least 10 to 15 minutes. This pause helps the interior set while keeping the fries ready for the second fry.
Heat Oil for the Second Fry: Increase the oil temperature to 375°F. Make sure the oil comes fully back up to temperature before adding another batch.
Second Fry (Crisping): Fry the blanched potatoes again, in batches, for 2 to 4 minutes until golden brown and crispy. Drain on fresh paper towels or a wire rack. Always let the oil return to 375°F before starting the next batch.
Season and Serve: While the fries are still hot, toss them with salt, pepper, or your homemade seasoning blend. Serve immediately with your favorite dipping sauces. Enjoy!