For almost 170 years, the brewery has only used pure ingredients: water, malt, hops, sugar and yeast. All this time they have made 100% natural beer with them. And with each investment, they aim for a better quality of the Trappist beer. That is the leitmotiv through the history of the brewery.

The brewery produces three beers. Westmalle Dubbel is a 7% abv Dubbel. Westmalle Tripel is a 9.5% abv tripel, was first brewed in 1934 and the recipe has not changed since 1956. It is made with pale candy sugar and has a very pale colour produced from a mash of light pilsener malts. Styrian Goldings hops are used along with some German varieties and the classic Saaz pilsener hop. After a long secondary fermentation Westmalle Tripel is bottled with a dose of sugar and yeast. Westmalle Extra is a 5% abv beer with limited availability, i.e. a patersbier. It has been speculated that Westmalle's choice of three types of beers was based on the Holy Trinity.