A pretzel is a type of baked bread product made from dough most commonly shaped into a twisted knot. Pretzels originated in Europe, possibly among monasteries in the Early Middle Ages. The traditional pretzel shape is a distinctive symmetrical looped form, with the ends of a long strip of dough intertwined and then twisted back into itself in a certain way ("a pretzel loop"). Pretzels now come in different shapes. Salt is the most common seasoning for pretzels, complementing the washing soda or lye treatment that gives pretzels their traditional "skin" and flavor through the Maillard reaction; other seasonings include sugars, chocolate, glazes, seeds, and/or nuts.