A country that traces its beer-making history back to the time of the Crusades, Belgium today is considered the most diverse beer producer in the world. Among the many stylistically individual beers it produces are abbey and Trappist beers.

Basically, Trappist beer must be brewed in a Trappist monastery, with the monks playing a role in its production. These beers tend to be strong-flavored. There are currently eight beer-making Trappist monasteries, all but two in Belgium.

Abbey beer can be made by any non-Trappist monastery — the Benedictines and Cistercians, for instance — and today are usually made by a commercial brewery in the style of abbey beer. They are similar to Trappist beers although usually less intense.

For centuries, all monastic beers were called abbey beer. Then, in 1997, the International Trappist Association announced the designation “Trappist Beer” could be used only for beer made in a Trappist monastery. Two years later, the Union of Belgian Brewers introduced the designation “Certified Belgian Abbey Beer.” At present, there are 18 certified abbey beers brewed in Belgium.

A fine example of abbey beer is produced by Brasserie de L’Abbaye du Val-Dieu in a centuries-old Cistercian monastery near the town of Aubel. A private family owns the brewery; the last Cistercian monks left the abbey in 2001. This is the only abbey beer actually brewed in an abbey.

Its three most popular beers are known by their color. Val-Dieu Blonde is fresh, delicious and pale with 6 percent alcohol. The 8 percent Val-Dieu Brune is chocolate brown, dense and piquant. Val-Dieu Triple, 9 percent alcohol, is aromatic, full-bodied and memorable.

A fine example of Trappist beer is Rochefort. While the name of the monastery is Notre-Dame de Saint-Rémy, its beer is named after the nearest town. The Trappists began making beer here in the 1500s, and today their three best known are named by numbers. Rochefort 6, with 7.5 percent alcohol, is the softest, a copper-shaded beer with a light, fruity aroma. Rochefort 8 is golden brown, 9 percent alcohol and boasts a more forward aroma and more robust flavor. Rochefort 10, at 11 percent alcohol, is a dark brown, full-bodied beer, firm and rich with a complex aroma reminiscent of fruits and chocolate.