Good French-fried potatoes must be blanched or precooked in hot oil before they are browned. In the blanching process the potato pieces are cooked and the water evaporated from them. After blanching they are drained, cooled, and ready for the final last-minute cooking in oil to make them crisp and brown. This blanching can be done hours in advance of the final frying. Idaho potatoes are best to use in all French-fried-potato recipes.