Serves 4

Rinse cut fries in large bowl under cold running water until water turns from milky colored to clear. Cover with at least 1 inch of water, then cover with ice. Refrigerate at least 30 minutes. (Can be refrigerated up to 3 days ahead.)

In 5-quart pot or in larger electric fryer, heat oil over medium-low heat to 325°. As oil heats, add bacon grease. Oil will bubble up when you add fries, so be sure you have at lease 3 inches of room at top of cooking pot.

Pour off ice and water, quickly wrap potatoes in a clean tea towel, and thoroughly pat dry. Increase heat to medium-high and add fries, a handful at a time, to hot oil. Fry, stirring with large-hole slotted spoon, until potatoes are limp and soft and start to turn from white to blond, 6 to 8 minutes. (Oil temperature will drop 50 to 60 degrees during this frying.) Use skimmer or slotted spoon to transfer fries to brown paper bag to drain; let rest at least 10 minutes. (Can stand at room temperature up to 2 hours.)

When ready to surve fries, reheat oil to 350°. Using paper bag as a funnel, pour potatoes into hot oil. Discard bag and set up second paper bag. Fry potatoes, stirring fairly constantly, until golden brown and puffed, about 1 minute. Transfer to paper bag and drain again. Season to taste with salt and pepper or seasoned salt. Serve immediately.