STEP ONE: THE RAW INGREDIENTS
Success begins with a careful selection of materials. Karen Schaich, a professor of Food Chemistry at Rutgers University (currently in the process of publishing a USDA-funded paper on the chemistry of French-fry crust), says that selecting a good potato is one of the most important steps in making a good fry. "You have to have a high-density potato, like a Russet Burbank," she says. "It's kind of like apples: Some are hard and dense and crisp. Soft, mealy apples brown a lot faster, and the same thing is true with potatoes. If you've got a soft potato, make mashed potatoes."
High-density foods are best for frying because if the item is too soft when tossed in the vat, the oil will soak through, making it difficult to attain a crispy crust at the surface and resulting in a soggy, oil-logged product.