Trappist beer is brewed by Trappist breweries. Eleven monasteries — six in Belgium, two in the Netherlands and one each in Austria, Italy and United States — currently brew beer and sell it as Authentic Trappist Product.
The order takes its name from La Trappe Abbey or La Grande Trappe, located in the French province of Normandy. A reform movement began there in 1664, in reaction to the relaxation of practices in many Cistercian monasteries.
Trappist beers are all top-fermented, including La Trappe Bockbier, and mainly bottle conditioned. Trappist breweries use various systems of nomenclature for the different beers produced which relate to their relative strength.
The best known is the system where different beers are called Enkel/Single, Dubbel/Double and Tripel/Triple. These terms roughly describe both the amount of malt and the original gravity for a Dubbel and triple for a Tripel, marking the casks accordingly. Enkels are now no longer brewed as such.