A quadrupel is a type of beer, with an alcohol by volume of 10% or more. There is little agreement on the status of Quadrupel as a style. Beer writer Tim Webb notes that similar beers are called Grand Cru in Belgium.
Quadrupel is the brand name of a strong seasonal beer La Trappe Quadrupel brewed by De Koningshoeven Brewery in the Netherlands, one of the eleven Trappist beers.
In other countries, particularly the United States, quadrupel or quad has become a generic trademark. The term may refer to an especially strong style of dark ale, with a characteristic spicy, ripe fruit flavor.