Trading 4s is a jazz term used to describe when two soloists play alternating four-bar phrases, as though they were having a lively conversation with chords.

In North Coast Brewing’s tribute beer to Jazz legend Thelonius Monk the brewery trades 4s not with musical instruments but with yeast and malt. The result is a playful duet in the chord of B (B standing of course for Belgium).

Brother Thelonious Belgium Style Abbey Ale takes its name from Thelonious Sphere Monk, one of the most influential jazz musicians to have lived, a pioneer of bebop and a masterful pianist. It is his face you see surrounded by a keyboard halo on the bottle’s front label.*

Brother Thelonious is a Belgium Style Strong Dark Ale, a largely unfamiliar type of beer here in Sweden (and therefore easily misunderstood). Beers of this style tend to be deep amber to dark brown in colour, hinting at the liberal use of rich malts. The Belgium yeasts used to brew them can produce a wide range of fruity esters leaning towards plums, raisins and prunes. Some phenol notes can also often be picked out, imparting a spicy peppery edge.

What all Belgium Style Dark Ales share in common is a robust alcoholic body. They generally weigh in between 8-11%ABV and therefore make ideal partners to dark meats, game, desserts and strong cheeses. Or, of course, for trading sips while chilling out to your favourite music.

When you pour up Brother Thelonious it’s clear that North Coast Brewing and the beer style police are playing off the same song sheet. A clear, shimmering coppery auburn body sits under a tawny coloured head that collapses quickly to a ring.

On the nose the malts push to the front with caramel, milk chocolate (think Dumle with booze) and toasted bread. There’s a discrete layer of raisins and of course the alcohol, in the form of a prune-based eau de vie, is ever-present.

The richness of the aroma doesn’t quite transfer into the taste for me, with the initial sweet caramel quickly thinning out, becoming more almondy and spicy (perfectly to style) and finishing a bit hot. I was hoping for a bit more of a velvety mouthfeel to smother some of the alcohol.

That said Brother Thelonious is a great example of its style. A perfect beer to age, I’m giving it a note-worthy 4.0 out of 5.

And all that jazz.

*For every bottle of Brother Thelonious sold a contribution is made by the brewery to the Thelonious Monk Institute of Jazz which provides support and education to some of the world’s most promising young musicians.