McDonald’s “World Famous Fries®” are made from premium Russet Burbank and Shepody potatoes, fried in vegetable oil, and are crispy outside and fluffy inside — 230 calories in a small serving. McDonald’s fries were introduced in 1949, originally cooked in beef tallow and cottonseed oil. Ray Kroc pioneered potato curing for crispness and later switched to frozen fries for consistency. In 1990, McDonald’s replaced beef tallow with vegetable oil after public health campaigns, and in 2008 eliminated trans fats in the U.S. and Canada. Today, fries are made from premium potatoes and fried in vegetable oil with beef flavoring for taste.