Trappist beers are brewed by monks of the Trappist Order. There are six Trappist breweries in Belgium: Westmalle, Westvleteren, Achel, Chimay, Orval and Rochefort. Also three Flemish Norbertine communities brew within the walls of their monastery: in Averbode, Heverlee and Grimbergen. Besides, many other Belgian breweries also brew abbey beers, through an agreement with an existing or historical abbey site. Abbey beers are known for their complexity and their characteristic fruity and spicy notes. The most common abbey styles are the ‘dubbel’ (6 - 7%) and ‘tripel’ (7 - 9%). The sweetish ‘dubbel’ (or ‘double’) is a brown beer, having flavours like caramel, raisin, or liquorice, with or without a slightly burnt finish. The blonde ‘tripel’ (or ‘triple’) is stronger and mostly hoppier than the ‘dubbel’.