On 22 April 1836 the Westmalle monastery became a Trappist abbey, good news for the monks as the change allowed them to drink beer with their meals. Hence, Abbot Martinus Dom ordered the construction of a small brewery the same year, leading to the monks enjoying their own beer for the first time on 10 December 1836.
In 1856 the monks started selling some of their beer at the abbey's gate. This proved so popular that the brewery was expanded, first in 1865 and again in 1897. In 1921, the abbey released its beer into wholesale distribution, leading to the construction of a new brewing hall in the early 1930s with a computer-controlled brewing hall following in 1991.
The Trappist beers the monks produce are top fermented and brewed with only: water (drawn from the abbey's own source and treated in its own plant), malted barley, hops, sugar and the abbey's own yeast culture.