Belgian dubbel or quadrupel: strength, colour and flavour

The abbey tradition

Belgium's Trappist monasteries have brewed for centuries, but the beers we know today mostly took shape in the 20th century. The monastery brewery at Westmalle is usually credited with the modern dubbel and later with the tripel. Abbey style beers brewed by secular breweries followed the same models.

The names are loose. Dubbel and tripel suggest double and triple strength relative to an everyday beer, though the relationship is not exact. Quadrupel came later. The term was used on a label by the Dutch Trappist brewery at Koningshoeven in the early 1990s. The name spread from there. The BJCP files these strong dark beers under Belgian dark strong ale. Our guides to Belgian dubbel and Belgian strong dark ale cover each in depth.

The numbers

• Dubbel: about 6 to 7.6% ABV, deep amber to copper brown, moderate bitterness.
• Quadrupel or Belgian dark strong ale: about 8 to 12% ABV, deep amber to dark brown, low to moderate bitterness with a fuller body.

A quad usually starts with much more sugar, so it finishes stronger and richer. Both are highly carbonated and bottle conditioned.

Flavour: dubbel

A dubbel tastes of dark fruit: raisin, plum and dried cherry, with caramel and a little toast. Belgian yeast adds esters and a light clove or pepper spice. The finish is moderately dry, which keeps it drinkable. It should never taste roasty or burnt.

Much of the colour and flavour comes from dark Belgian candi syrup or caramelised sugar, not just from specialty malts. Sugar ferments almost completely, which is why the beer can taste rich without being heavy.

Flavour: quadrupel

A quad takes the same flavours further. Expect fig, date, prune, dark caramel, toffee and sometimes chocolate or port like notes. Alcohol is noticeable as warmth but should not be hot or solvent like. The body is fuller and the sweetness higher, though the best examples still finish drier than you expect for the strength.

Quads also age well. Over a year or two, the alcohol softens and dried fruit notes deepen. A dubbel can age a little but is usually at its best within a year.

Not to be confused with tripel

The Belgian tripel sits between the two in strength, around 7.5 to 9.5% ABV, but it is pale gold, not dark. Its flavour is spicy, fruity and dry, with more hop character. It belongs to a different branch of the family despite its name.

How brewers make them

Both beers start with pilsner or pale malt, often with some Munich, aromatic or a small amount of caramel malt. Much of the colour and dark fruit comes from dark candi syrup added to the kettle. Sugar thins the body slightly and ferments almost completely, which lets a strong beer finish surprisingly dry.

Yeast choice and temperature shape the rest. Belgian abbey strains are often pitched in the high teens and allowed to rise into the low to mid 20s °C as fermentation runs, which builds fruit and spice. If it runs too hot, the yeast throws harsh fusel alcohols that taste like solvent. In an Indian summer without temperature control, that line is easy to cross. The beer is then bottle conditioned with fresh sugar and yeast to reach its high carbonation.

Serving and food

Serve both in a chalice or tulip glass. Dubbel is best at around 8 to 12 °C and quad slightly warmer, 12 to 14 °C. Very cold temperatures mute the fruit and spice.

Dubbel pairs with food easily: roast chicken, mutton curries with caramelised onions, mushroom dishes, aged cheese and even a good dal makhani. Quad is better after dinner, with dark chocolate, plum cake, nolen gur sandesh or on its own in a small glass. At 10% or more, a 330 ml bottle shared between two or three people is plenty.

Tasting them side by side

Taste the dubbel first, then the quad, because the stronger beer will flatten anything after it. Notice the colour, then the aroma: raisin and clove in the dubbel, fig and toffee in the quad. On the palate, compare body and alcohol warmth. Finish with a glass of water between beers.

It is easy to say the quad is stronger. The harder skill is describing what the extra strength does to body, sweetness and spice. Then judge whether the alcohol is well integrated. Brewing these beers also requires judgement about sugar, yeast health and fermentation temperature, because Belgian yeast left too warm produces harsh fusel alcohols.

Common questions

What is the difference between a dubbel and a quadrupel?

Strength and intensity. A dubbel is about 6 to 7.6% ABV with raisin and caramel; a quad is 8 to 12% with richer fig, toffee and more alcohol warmth.

Is a quadrupel four times as strong as a normal beer?

No. The name is traditional, not a precise measure. Most quads are 8 to 12% ABV.

Can I age Belgian dark ales?

Quads age well for one to two years if stored cool and dark. Dubbels are usually best within a year.