When it comes to winemaking, the importance of oak barrels is well known, but cooperage is just as crucial for making Bourbon. That’s why distillers are experimenting with new techniques ranging from inserting French oak staves to charring their casks for longer to ensure the best Bourbon flavors are achieved. In Kentucky, once the cask is filled with whiskey, distillers store the barrels in warehouses referred to as rickhouses—wooden structures that take you back to the days when wood beams anchored buildings and wrought-iron latches clamped doors shut. Traditional Kentucky rickhouses are made with limestone rock exteriors and are several stories high, but aluminum-skinned exteriors have become popular because it allows the warehouse to breathe. Some distilleries have even experimented with climate-controlled warehouses in an effort to speed up the aging. But, it’s far more common for a distiller to play with barrel aging than to modify a 50- to 200-year-old rickhouse.
When making Parker’s Heritage Collection, Heaven Hill Distilleries transfers the 10-year-old Bourbon from Bourbon barrels to used Limousin Oak Cognac barrels. The Parker’s Heritage Collection Bourbon is then aged, or finished, for another six months in these toasted barrels that once aged Cognac for two to three years. This gives the whiskey a subtle Cognac flavor with notes of dried apricot and walnut.
After aging Bourbon for a minimum of four years, the Louisville Distilling Company places Angel’s Envy Bourbon into Port barrels, where it ages for another six months. By finishing it in Port barrels, the Angel’s Envy Bourbon carries the rich aromas of Port and Bourbon with notes of caramelized apple, chocolate and smoke.
For its Master’s Collection, the Woodford Reserve Distillery finished one of its Bourbons in toasted maple-wood barrels. The result is the Maple Wood Finish Bourbon, filled with notes of maple, honey and brown sugar.
Meanwhile, the Maker’s Mark Distillery took an ode from winemakers inserting staves. For its Maker’s 46, the distillery’s first new product in 50 years, toasted French oak staves are inserted into the American oak barrel that had been aging Maker’s Mark. With the new staves in place, distillers pour Maker’s Mark back into the barrel and the product ages for a few more months. This amplifies the rich caramel notes, giving Maker’s 46 a woodier nose without the burnt smoky flavor and adding more alcohol proof for a longer finish.
And then there’s Buffalo Trace’s Single Oak Project Kentucky Straight Bourbon Whiskey, which is distilled in single American white oak tree barrels. To date, 96 trees from the Missouri Ozarks have yielded 192 barrels. The staves are air-dried, seasoned and charred for 55 seconds. There are two recipes—either wheat or rye Bourbon—and two proofs—105 or 125 proof. The barrels are aged in two completely different warehouses, one with wooden ricks and one with concrete floors. This gives the Single Oak Project seven different variables to create the flavor.
There are also micro-distilleries, including New York’s Tuthilltown Distillery, aging bourbon in mini-barrels in an effort to get more surface contact with wood. After the Bourbon barrels are used, they are sold to Scotch, Tequila, wine, beer and even soy sauce manufacturers.
To read about the Kentucky Bourbon Trail, click here.