There are rum releases, and then there are moments. The Foursquare Penultimus — Mark XXX in the Exceptional Cask Selection — is the latter. As the penultimate chapter in Richard Seale’s defining series, it carries the weight of 18 years of ECS releases, and the knowledge that only one more will follow. Whether you are a longstanding Foursquare collector or encountering the ECS for the first time, this is a bottle that demands attention.

What Is Foursquare Penultimus?

Foursquare Penultimus is a 15-year-old single blended rum from the Foursquare Rum Distillery in Barbados, released as Mark XXX — the thirtieth edition — of the Exceptional Cask Selection. “Penultimus” means second to last, and the name signals exactly that: this is the penultimate ECS release before Richard Seale brings the series to a close with Mark XXXI, the Epilogue.

The Penultimus is produced without added sugar, colouring, or filtration — hallmarks of Foursquare’s commitment to transparency that Richard Seale has championed throughout his career. If you want to understand what unchillfiltered spirits look like in practice, our guide to unchillfiltered spirits covers the detail.

The Exceptional Cask Selection: Why It Matters

The ECS is not simply a product line. Over 18 years it has become one of the most respected limited-release rum series in the world — a benchmark against which premium Barbados rum is measured. Each release is hand-selected and blended by Richard Seale, fourth-generation master distiller at Foursquare, and numbered sequentially in Roman numerals. No two releases are the same.

The series began in 2008 with a 1998 single vintage and has since expanded to include dual maturations, rare wine cask finishes, and complex blends of pot and column still distillates. Bottles that retailed for under £40 in the mid-2010s now command multiples of that on the secondary market — a trajectory that reflects the growing recognition of premium rum as a serious collector’s category.

Production and Maturation: What Makes It Different

Foursquare produces single blended rum — a blend of distillates from both a copper double-retort pot still and a continuous twin-column still. This combination gives Foursquare its characteristic structure: the column still provides freshness and precision; the pot still adds weight, complexity, and the oily, textured mouthfeel that distinguishes premium aged rum from lighter commercial styles.

Dual maturation explained

The Penultimus uses a dual maturation approach that has become a signature of the later ECS releases:

• One component is aged for 10 years in ex-bourbon casks, then transferred to ex-Moscatel casks for a further 5 years — 15 years total.
• A second component matures for the full 15 years in ex-bourbon casks alone, providing the backbone structure and vanilla foundation.
• The two are blended by Richard Seale to achieve balance between the ex-bourbon richness and the Moscatel’s dark fruit and dried grape complexity.

All ageing takes place under tropical Barbados conditions, where the heat accelerates maturation significantly. A 15-year-old tropical rum has undergone substantially more interaction with the wood than a 15-year-old Scotch matured in cooler Scottish warehouses.

The result is bottled at 57% ABV — the new standard strength for ECS limited releases — unchillfiltered, at natural colour, with no added sugar or flavourings.

Tasting Notes

The Moscatel cask influence is handled with notable restraint. This could have been an overtly sweet, fruit-forward rum — instead, Richard Seale has used the Moscatel to add dimension rather than sweetness, building on the ex-bourbon foundation rather than replacing it.

Collector Value and Rarity

The ECS series has a documented secondary market trajectory. Bottles that retailed at under £40 in 2015 now sell at auction for substantially more, and the announcement that Penultimus and Epilogue will close the series has accelerated collector interest considerably.

• The Penultimus is the second-to-last ECS release ever. Once the Epilogue sells out, the series is closed permanently.
• This is the first ECS to use Moscatel casks, making it a genuinely unique expression within the series.
• ECS bottles are issued in limited batches with no fixed schedule — they do not return to retail once sold through.
• At £100 retail, the Penultimus represents one of the strongest price-to-quality ratios in premium aged rum, with meaningful upside for collectors who hold rather than drink.

Verdict: Is the Foursquare Penultimus Worth Buying?

Yes — without qualification. The Penultimus is not just an excellent rum; it is a historically significant one. As the penultimate ECS release, it closes a chapter in Caribbean rum history. The dual Moscatel maturation delivers something genuinely new within the Foursquare style: darker, more complex, with a finish that outperforms every earlier ECS release we have tasted.

For collectors, this is essential. For enthusiasts who drink their bottles: buy two. For those encountering the ECS for the first time, the Penultimus is an ideal entry point — though be aware the Epilogue will follow, and that will be the last one.

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Frequently Asked Questions