The McDonald’s Corporation most likely drew on these advances when it eliminated beef tallow from its french fries. The company will not reveal the exact origin of the natural flavor added to its fries. In response to inquiries from Vegetarian Journal, however, McDonald’s did acknowledge that its fries derive some of their characteristic flavor from “an animal source.” Beef is the probable source, although other meats cannot be ruled out. In France, for example, fries are sometimes cooked in duck fat or horse tallow.