From The Food Encyclopedia by Jacques Rolland and Carol Sherman
A variable term that can mean the cooked outer layer of a food, such as the dough used to enclose or cover a pie filling; the crisp, cooked bread base of a pizza; or the hard, outermost layer of a loaf of bread. A crust can also form on the outside of a cooked piece of meat that has been rubbed with spices, flour or cornmeal. It is also a term for the sediment that forms inside wine bottles when they are aged for a long time.
