This story was first published on in February 2021.

The beginnings of spirits maturation, particularly with whiskey and rum, were by happenstance. Shipped long distances down rivers or across oceans in wooden barrels, the spirits held within not only gained color, but also new and enhanced flavors. In recent decades, that layman understanding has gained an ever-growing scientific footing, culminating in a scene today with numerous exciting projects underway, some of which take the concept of maturation back to its roots.

Bringing the Barrels Back to the Water

Jefferson’s Ocean Bourbon first made waves in 2012, after sending barrels of whiskey on meandering oceanic voyages, in which the whiskey being transported aboard its vessel sloshed within the casks, agitated by the constant movement of the ship on the tides. The liquor within the barrels matured, as the barrels on board were exposed to the elements. This singular product represents a portion of what Jefferson’s produces, but at newcomer O.H. Ingram River Aged Whiskey, maturing whiskey on the water represents their core ethos.

“My family has been working on the river for more than 150 years—it’s our lifeblood—and Ingram River Aged Whiskey is the latest evolution of this relationship,” said founder Hank Ingram. He sources distillate from MGP, and fully matures it on a specially designed barge floating on the Mississippi River, moored to the riverbank in Wickliffe, Kentucky, and equipped with a rickhouse which can hold up to 2,000 barrels.

“Here, our barrels are constantly exposed to the climate of the river and its drastic rise and fall,” Ingram said. The impact includes a large diurnal temperature shift, constantly working the whiskey in and out of the wood, and the movement of the river itself, which also agitates the spirit held within the cask. This is in addition to an overall humid environment on the water, quite different from what you’d find in a typical warehouse.

At Maison Ferrand in Cognac, France, innovation has always been the name of the game, though that innovation is often rooted in historical enterprises. “Our DNA is to search in the archives for old techniques and modernize them with the latest research and technology,” said Margaux Lespinasse, Maison Ferrand’s private casks manager. Back to the water it was, then, with the forthcoming Pierre Ferrand Barge 166 set to be unveiled spring 2021.

Barge 166 will be a floating maturation laboratory on the Seine, while also serving as an events space and an opportunity to offer tailor-made products for individual purchasers of private barrels. “The idea came to [cellar master and owner] Alexandre Gabriel after numerous studies on the sea voyages of our rum barrels from their countries of origin,” Lespinasse said.

As opposed to their typical warehouses, filled with used bourbon or Cognac casks ranging from 220 to 300 liters in size, the barge will hold small, 30-liter casks. The smaller barrels will be used for the maturation of Cognac and rum and were chosen on purpose, with the intention of monitoring their interactions with the unique environs of the river. “We’ll study the very humid environment where our casks will be aged—or its hygrometry—the humidity on a boat floating on a river will be very high,” Lespinasse said. “In an air saturated by water, the alcohol is evaporating particularly intensely, and the direct effect is a decreasing of the spirit’s level of alcohol. The result is a very round, smooth, and elegant profile.”

Here also, temperature shifts as well as the movement of the river will impact the end result. That end result, though, is still but a theory at this point, though monitoring the results of the experiment is both entertaining and educational. “Combining small casks and a very humid environment will probably change what we know about the maturation of our spirits,” Lespinasse said.

Going for a Deep Freeze

Back stateside, Buffalo Trace Distillery has long stood out among the big bourbon producers for an intensive, forward-thinking approach toward maturation. Case in point is their warehouse X initiative, launched in 2013, with rigorous monitoring of myriad maturation conditions including temperature, pressure, air flow, exposure to sunlight, and more.

A newer venture, warehouse P, is focused on one area alone, bringing the temperature of the warehouse down as much as possible to slow the maturation process down in turn, in an attempt to produce an ultra-aged bourbon that can stand alongside the super premium 50-plus-year-old Scotch whisky on the market. The climate in Kentucky versus Scotland, and bourbon’s usage of new charred versus used oak casks, wouldn’t allow for such an extended period of aging if the barrels were left to their own devices. There would be far too much extraction from the wood creating over-tannic whiskeys, while the angel’s share would be lofty enough over a period of that length that there would simply be no whiskey left in the barrels. But what if a bourbon barrel was stored in a refrigerated warehouse at approximately 45 degrees?

“We want to give American whiskey the same footing as Scotch, and to do that, we know we need to slow down the aging process,” said Harlen Wheatley, Buffalo Trace master distiller. “How do we do that? By controlling the temperature. We know that below a certain temperature, whiskey will stop aging, so we are experimenting in a temperature range slightly above this point so we can slow down but not stop the aging cycle. The results to date are very encouraging—it’s working.”

A potential half-century-old Buffalo Trace barrel will fall under the banner of The Last Drop, a venture specializing in one-off releases of super old and rare spirits, now a stablemate of Buffalo Trace under parent Sazerac Company. But rest assured, Wheatley has a few other tricks up his sleeve for warehouse P. “We have multiple recipes—not just whiskey—and barrel types all being explored,” he said. “The singular focus of warehouse P is to support the goal of our broader Holy Grail project, which is to continue to push ourselves to produce even greater whiskey.”

From the river to the freezer, spirits are finding new, and sometimes old, environs to be stored within, while the results being enjoyed today and in the years ahead are very much scientific and modern as opposed to anecdotal and happenstance.