Review: Foursquare Mark XX “Isonomy” Single Blended Rum

Review: Foursquare Mark XX “Isonomy” Single Blended Rum

To all those rum fans out there, I promise we’re trying to stay up to date on our Foursquare coverage, but running down samples of these rare rums is sometimes difficult. Today, we’re taking a look at a recent-ish release from January 2022.  Isonomy is the 20th release in the Exceptional Cask Selection Series, and it is also the oldest rum yet from the famed Bajan distillery, clocking in at an impressively mature 17-years-old. As is typical from Foursquare, this a single blended rum (both pot- and column-distilled) with no added sugar or flavorings. Let’s check it out.

These bottles seldom disappoint, and this latest offering is no exception. In fact, it’s probably the best thing I’ve had yet from Foursquare. The nose is intense and rich with a heavily caramelized sweetness showcasing notes of treacle, molasses, and brûléed sugar. At the same time, it’s surprisingly fresh with softer undertones of light brown sugar that build as it opens alongside toasted coconut, chocolate-covered cherry, and gentle baking spice. It’s as engrossing an aroma as I’ve encountered in a rum; the smell I imagine might fill Foursquare’s barrel storage in Barbados.

The palate is big, rich, and beautifully balanced. It’s also probably the easiest drinking overproof Foursquare I’ve encountered since the 2005. The flavors aren’t as bold as other high-octane releases, like the 2008, but there is an incredible depth and complexity to this one that brings out a unique elegance. Silky notes of brown butter, snickerdoodle, and sugary pralines give way to a syrupy, fruit cocktail of Bing cherry, pineapple, banana, and melon. A bit of chocolate mint and bright citrus give a refreshing, airy dimension to such a deep, rich spirit. The finish is warming and long with oatmeal raisin cookies, candied pineapple, and spicy Mexican chocolate. Simply stunning and an easy contender for our best rum of 2023. Even if it did hit shelves last year!

116 proof.

A / $150 /

Foursquare Mark XX "Isonomy" Single Blended Rum




Drew Beard is assistant editor for Drinkhacker and winner of several booze-related merit badges, including Certified Specialist in Spirits and Executive Bourbon Steward. A former federal employee turned hotelier and spirits journalist, he looks forward to his next midlife crisis.

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