This is an interesting concept. The whiskey barrels are actually stored on the open decks of cruise ships for six months.
Here’s a Reddit thread where someone saw one of the actual barrels:
Not sure I understand the significance of aging the barrels stored on an open deck. Will that affect the flavor profile differently than if aged below deck?
These have been available for many years. Some of the early releases are pretty sought after, but that’s because they used whiskey from the defunct Stitzel-Weller distillery. I think the actual method is 95% a gimmick. (Yes yes, temperature changes and sloshing would matter a bit).
Whiskey aged for six months is certainly go straight to the top of one of my lists. Can you guess which list? 
It’s not aged for 6 months, that’s the at-sea portion.
I know if the whiskey is aged in an environment where the temperature fluctuates between very hot and relatively cool, it will age better. More whiskey would expand into the wood of the barrel as it gets hot and then contract out of the wood as it cools. I don’t see the deck of a ship getting hotter than the top shelf of a barrel house.
I have to wonder about this idea, though: Would the barrel absorb the salt from the air? Otherwise I see no advantage other than novelty.
They are claiming the temperature swings, the rocking and salt air are factors.
Is it available yet? A simple blind taste test between it and the original matured batch should tell us what we need to know.
A friend of mine is co-owner of a small-batch bourbon and whiskey distillery; aging their products in barrels that spend several months on Lake Michigan, on fishing boats, is one of their company’s main selling points.
My friend, who’s worked in the liquor industry for 30 years, tells me that 3 or so months on a boat, with the liquor rocking and sloshing around in the barrel, is roughly equivalent to several years’ worth of aging in a barrel in a warehouse or cellar.
I’m not super-knowledgeable about whiskies, but I enjoy them, and their products taste very good (and have won awards).
This is their company:
Sounds like a gimmick to me. Exposure to salt water increases the chance of some of it getting into the whiskey. i doubt salt water diluted whiskey is an improvement, but i could be wrong. All the sloshing about, if that does improve it, can be easily rigged up in a rickhouse.
I don’t know that it “improves” it, per se; AIUI, what the sloshing does is speed up the aging process. As well, of course, as providing a marketing hook.
Jefferson’s Ocean has been around since 2012. I’ve seen it available near me a number of times and have never bothered.
Yeah. As long as more years aged → more dollars price, we won’t see quickie aging ashore in an ordinary rickhouse.
But if it can be aged to a decent age ashore, then the flavor upgraded with some sloshing offshore, then the price upgraded for the cachet / rarety / hipster value of offshore sloshing, this could be the next big fad.
They get a more premium product sooner, and we get a more premium product at a (commensurate?) more premium price.
The water used, the tilth of the grain, and exposure to elements matter, even without the sloshing. I’ve visited several distilleries that have saltwater-adjacent warehouses for particular casks.
Sea air is half the charm of Islay whiskies. (The other half is the robust peating of the malt.)
But six months feels like a marketing gimmick to me.
If aging aboard ship significantly improved the flavor of rum, Royal Navy seamen who were issued a daily ration on long voyages would’ve noticed a big difference over time. Officers traditionally were allowed to drink whiskey, but I don’t know if they brought it on board in barrels.
As I and others have noted: months on a moving ship or boat – either at sea or on a large lake – do, in fact, age a whiskey significantly more rapidly than it would age if it were sitting still in a barrel in a warehouse.
Yes, it’s a marketing gimmick, but it also has an actual effect.
Not all barrels will have much of an impact on a liquor, as far as aging goes.
AIUI, it needs to be the right sort of wood – typically one of several oaks – and usually the inside surface of the barrel needs to be charred for it to be a good vessel for aging the contents.
If the rum wasn’t being carried aboard those ships in barrels which were made for aging, it might not have aged the rum in any sort of noticeable or palatable way.
What the time on board a boat/ship, and the sloshing, does for the whiskies and bourbons in this discussion, AIUI, is that it brings more of the liquor into more frequent contact with the charred surface of the barrel interior.
4h wrote:
Not sure I understand the significance of aging the barrels stored on an open deck. Will that affect the flavor profile differently than if aged below deck?
It marinates to the music of flute-playing virgin Sicilian girls.
Do you have a cite that the effect is significant other than your friend that has an monetary interest in the claim?