Trappist is a particular category of beers, or more precisely an indication of origin, which includes various styles that are brewed in Trappist monasteries. Trappist beers are internationally certified and can only be produced by Trappist abbeys—which include six located in Belgium and two in the Netherlands, while Italy, Austria, England, France, the United States, and Spain all have one certified Trappist brewery.
All abbeys develop their yeast, and the regulations also stipulate that the beer must be brewed within the immediate surroundings of the abbey and that the entire production needs to be supervised by monks. Similar beer styles that are produced in non-Trappist monasteries are usually referred to as Abbey-style beers.
They are unpasteurized, have no chemical additives, and sugar is typically added to the wort (the liquid extracted from the mashing process). All Trappist beers are bottle-conditioned—meaning that the yeast is allowed to carbonate the beer after the fermentation is complete.