In February 2020, Covid-19 cases erupted aboard the cruise ship Diamond Princess off the coast of Yokohama, Japan. At the time, the ship housed the largest cluster of cases outside of mainland China. In the weeks that followed, stock prices of the likes of Carnival and Royal Caribbean plummeted, as analysts predicted the cruise industry had permanently sunk.
Just a few years later, the cruise and sailing world isn’t merely recovering — it’s shattering records. With its endless horizon and pristine shimmer, the thrill of exploration, and the mystery of the planet’s least understood biome, the allure of the ocean is proving stronger than the PR nightmare of the Covid-19 years. It’s a fascination that has captivated humanity for centuries, inspiring epic poems, daring explorations, blockbuster films, luxury travel, and numerous drinks, too.
Historically, much of the world’s alcohol would be transported in wooden barrels by ship. These voyages were a necessity rather than a choice, and any influence on the liquid would be simply accepted as part of the process. Yet merchants and producers soon realized that the journeys themselves could have an impact. The constant rocking of the ship, the heat of the sun, the humidity, and the dramatic temperature swings of long global routes would all affect the spirit inside the barrel. Often this was incidental, but in some cases it led to distinctive characteristics, occasionally giving rise to unique products or even entirely new categories.
The quintessentially oxidised character of Madeira wine, for instance, is said to have emerged during the long sea voyages required to transport it from the island to overseas markets. Throughout the journey, constant movement and the persistent heat of the sun effectively “baked” the liquid, transforming it into the world’s most delectably indestructible wine. The maritime influence became so integral to the style that Madeiran winemakers swear by it to this day. Traditional wines are now aged in hot lofts that replicate the heating effect once created naturally at sea, while larger-scale operations adopt the “estufagem” technique (literally “stoving”) in stainless
steel tanks.
Whisky was once often transported on long sea voyages, too. “Back in the early 1800s, when [American] distillers were trying to get whiskey to population centres, they first put it into barrels and floated it downriver on flatboats,” says Trey Zoeller, founder of Jefferson’s Bourbon. Once in New Orleans, he explains, the barrels could be traded locally or loaded onto seagoing ships, sailing around Florida to reach more profitable cities like Philadelphia, New York, and Boston. “I think that’s what transformed ‘whiskey’ into ‘bourbon’ for the first time,” he argues.
Large quantities of whisky are still transported by sea today, but the shorter duration of modern voyages, combined with the fact that much of it now travels as finished product in sealed bottles, means any impact on the liquid is negligible. Yet some distillers, still drawn to the ocean, are deliberately returning to maritime ageing in search of the distinctive, mature character that can develop when spirit sloshes inside barrels aboard a ship, where constant motion and shifting conditions encourage a more kinetic interaction between wood and liquid.
Zoeller himself is responsible for one of the most notable examples. Identified by its voyage number, each release in his Jefferson’s Ocean series is based on Jefferson’s Reserve Bourbon that has already aged for at least six years in Kentucky. The barrels are loaded into shipping containers designed to expose them to the elements during lengthy voyages (up to eight months), allowing the motion, temperature swings, and maritime conditions to impart a distinctive character to the whiskey. “We take the whiskey from Kentucky and place it into shipping containers with sunroof-like openings so the barrels are exposed to sun, rain, and snow,” Zoeller explains. “From there, it is loaded onto the top of a ship in Savannah and embarks on a global journey, through the Caribbean, Pacific, and Atlantic, touching dozens of ports, crossing the equator twice, before finally returning to Kentucky.”
Other distilleries let the liquid spend far less time at sea. English whisky maker Adnams, for instance, released a limited-edition single malt from a nine-year-old cask that spent 103 days sailing the high seas aboard Olsen Cruise Lines’ ship, the Borealis. According to the project partners, the whisky’s constant motion increased its contact with the wood, enhancing both colour and flavour through intensified caramelisation of the barrel’s sugars. Meanwhile, salt-laden air was said to penetrate the cask, contributing subtle saline notes as evaporation occurred during the voyage.
High-rye Kentucky bourbon Never Say Die is subject to an even shorter journey. After full maturation in Kentucky, the barrels spend six to eight weeks at sea while travelling from Florida to Liverpool, before being transported by land to White Peak Distillery in the Peak District for an additional year of maturation. “We were delighted to see that the ocean trip… genuinely enhanced the whisky’s complexity and quality, which has encouraged us to continue despite the extra cost and effort,” says Never Say Die co-founder Brian Luftman. “When we compare barrels side by side against those that have remained solely in Kentucky, we consistently notice a greater sense of roundness and integration in the sea-travelled whiskey. The constant motion during the Atlantic crossing increases agitation between the spirit and the charred oak, encouraging deeper interaction with the wood. In our experience, this results in a more developed texture, softened edges, and a more cohesive expression of oak, spice, and sweetness.”
The most skeptical whisky enthusiasts might dismiss the modern revival of sea ageing as pure gimmickry, yet even they must recognise the genuine challenges and risks distillers face when sending their whiskies across the high seas. “Running a transatlantic production operation is a logistical nightmare,” says Luftman, highlighting the bureaucratic hurdles involved: “multi-currency transactions, tariffs, customs clearance, keeping our product under bond, and those are just some of the major issues.”
Indeed, sea ageing can complicate even the most basic processes of whisky production. On land, barrels can be monitored and repaired if necessary. But once at sea, they become inaccessible until they reach the final destination, which can lead to dramatic surprises upon arrival. “Leakages are a big problem,” Zoeller explains. “In Kentucky, a leak is easy to spot, as there is usually a puddle on the ground. But once the barrels are on the ship, they are out of sight. We haven’t lost a container yet, but we have certainly ‘lost’ barrels. You open the container, and find one or two completely dry.” Conventional on-land maturation also allows regular sampling to monitor a barrel’s progress. With sea ageing, that oversight, too, is removed, leaving the master blender unaware of how the flavour is developing until the voyage is complete.
Even more drastic is the influence of weather and sea conditions on the final profile of the spirit, which can translate into inconsistent results both between shipments and among barrels of the same batch. Extreme events and intense heat, for instance, can accelerate evaporation or extraction. “Along the way, the ship might encounter hurricanes, dead seas, or cyclones,” Zoeller says. “When we are in very rough seas for an extended period, we lose more to evaporation, which concentrates the liquid and makes it brinier. Plus ships lose containers all the time. Knock on wood, it hasn’t happened to us yet, but each journey is an unknown.”
Some have taken sea ageing to the extreme by exploring how liquids mature underwater, rather than above
it. This practice has been gaining traction for some time in the wine world, with countless producers worldwide (including champagne houses like Leclerc Briant and Veuve Clicquot) experimenting with it. Winemakers and blenders often find that gentle, constant movement from sea currents, combined with stable, cool underwater temperatures, benefits the liquid.
The application of this technique to whisky is a more recent phenomenon. “Around 2016–2017, some friends approached me to see if I was interested in ageing whisky under the ocean,” says Benjamin Kuentz, founder of the namesake French Maison. “They had already been doing it with Champagne and still wine for something like 10 or 15 years and continue to do so today.” Convinced by the idea, Kuentz launched what he dubbed Uisce de Profundis, a series of undersea-aged whiskies first released in 2020. His process involves submerging bottles of fully mature whisky at a depth of around 20 metres off the coast of Brittany for about a year. The bottles are then blended and rebottled before release, to ensure consistency. “I immediately realised how much I enjoyed this whisky. For me, it was made for gastronomy. It carries a subtle saltiness from the sea that pairs perfectly with oysters and seafood. The texture is very different from my usual whisky,” he adds. “It’s positively influenced by osmosis through the corks and by dynamic exchanges between wood and spirit driven by tidal pressure.”
Exploring the effects of the sea, whether above or below the surface, might appear at first like a purely academic exercise, but is in fact a response to humanity’s enduring, natural pull towards the oceans. It’s an innate fascination and respectful awe for the stage of some of humankind’s most momentous achievements and dramatic developments. A mysteriously cryptic yet utterly bewitching world that, even in the age of self-driving cars, remains less understood than the surface of the Moon.
