Once bourbon is ready to move from barrel to bottle, that barrel is up for grabs—since under U.S. law bourbon can be aged only in new oak. There’s a long tradition of distillers in Scotland, Japan, and Ireland buying used bourbon barrels to mature their whiskies, but more recently a bourbon barrel’s life has expanded well beyond whisky. “The great thing about bourbon barrels is their versatility,” says national educator for Don Julio tequila Jorge Raptis. “They’ve become popular for aging a variety of products—even cooking sauces and chocolates—but most notably other spirits outside of whisky.”
Indeed, oak-aged expressions can be found for nearly every spirits type. In rum, there’s Don Papa from the Philippines, Santa Teresa 1796 from Venezuela, and Mount Gay from Barbados, to name just a few. Tequila is similarly abundant in oak-aged expressions from brands including Don Julio, Lunazul, Ocho, Espolòn, and more. Even typically unaged spirits are getting in the game: Philadelphia Distilling, New Riff Distilling, KO Distillery, and Caledonia Spirits all offer gins aged in either new or used American oak barrels. There’s even an oak-aged vodka on the market from OYO Distillery.
The wine world has also joined in. “When we launched our 1000 Stories bourbon barrel-aged zinfandel back in 2014, it was the first widely available wine of this kind,” notes Bob Blue, winemaker for Fetzer winery’s 1000 Stories label. “Folks were absolutely ready to experience wine in this new way—our sales skyrocketed.”
American oak is used for aging spirits of all kinds, and for some very good reasons. For starters, American oak is chock-full of sweet compounds that offer flavors of vanilla and toffee, while it is also porous enough to allow for sufficient levels of oxidation. There is also the practical issue of supply: American oak barrels tend to be more abundant than most barrel types, and therefore are easy to acquire once bourbon producers are done with them.
Familiar, Yet Different
Bourbon’s popularity is undeniable, so it makes sense that other spirits producers and wine makers would look for ways to attract bourbon fans. Aging and finishing in bourbon oak accomplishes that goal, as it imparts familiar bourbon-like flavors. “Our Russian River Valley Pinot Noir Woodford Reserve Barrel Finish gives bourbon lovers an opportunity to try something different, but with a familiarity they’ll enjoy,” says Zidanelia Arcidiacono, who makes the pinot noir for California winery Sonoma-Cutrer—which has an inside track on barrel supply as it’s owned by Brown-Forman, also owner of Woodford Reserve and Old Forester, as well as Tennessee whiskey Jack Daniel’s. “It works the opposite way too: I love pinot noir, and find myself delighted by the bourbon-barrel flavor in this wine.”
Still, American oak is very different from other types of wood traditionally used to age wine. “A bourbon barrel gives you a completely different aroma and flavor profile—you’ve got to understand how much it will change your product,” says Arcidiacono. “Bourbon barrels are charred at high temperatures rather than toasted the way French oak wine barrels are. The charring allows for some caramelization on the interior surface of the barrel, and any liquid you put inside will absorb aromatic and flavor compounds like caramel, hazelnut, spices, and honey.”
“People the world over love the sensorial characteristics American oak imparts on spirits, from bourbon to scotch to tequila to cachaça,” says Novo Fogo marketing director Luke McKinley. “When people first try our barrel-aged cachaça many say, ‘This tastes like bourbon!’ to which we add, ‘Yes, it tastes like American oak because bourbon tastes like American oak!’ Ultimately, the barrel-aged cachaça is both recognizable and totally unique because of this combination of North American wood and South American spirit.”
Seeking to attract American whiskey fans over to the world of French cognac, Martell Cognac released Blue Swift—a base of VSOP cognac aged in French oak casks and finished in bourbon barrels—in 2016. (The product’s finish in bourbon barrels means it can no longer legally be called cognac and is instead referred to as a “spirit drink.”) The cognac’s delicate candied fruit and plum flavors are complemented by the notes of vanilla sweetness and toasted oak from the bourbon barrels.
For 1000 Stories, bourbon-barrel aging began as an experiment with its zinfandel, but the winemaking team was so impressed by the results that it expanded the portfolio to include a bourbon barrel-aged red blend, cabernet sauvignon, and chardonnay. “These wines are different—period,” Blue says. “The bourbon barrels add texture and richness to the wine, especially with the added mid-palate that comes from the influence of the whiskey that lingers in the wood. It’s just something you don’t see with traditional winemaking.”
Trinchero Family Estates has found a rapt audience for its Ménage à Trois Bourbon Barrel cabernet sauvignon. “Aging cabernet in bourbon barrels is all about taking what’s best about the wine and making it even more flavorful,” says Trinchero senior vice president of winemaking Glenn Andrade. “Bourbon softens heavily charred barrels, making them ideal candidates for aging wine. The barrels also impart smoky notes along with flavors of marzipan, cinnamon, and nutmeg—all great nuances for cabernet sauvignon. Just three months of aging in bourbon barrels goes a long way.”
For its bourbon barrel-aged wines—including a chardonnay, cabernet sauvignon, and red blend—Beringer Bros. sources used American oak barrels and ages its wines in them for 60 days. “The average age of our barrels is 4 years—we’ve found that older used barrels allow for a better integration of flavors,” says Beringer Bros. winemaker Ryan Rech. “Used bourbon barrels tend to impart fewer tannins but are still intense, with great flavors of vanilla, coconut, dill, and sawdust.”
Blue of 1000 Stories also prefers aging in older barrels, which he sources from a variety of Kentucky distillers, because they impart more bourbon character to the wine. “Older barrels add mature vanilla and spice aromas without the intensity of raw wood, which can be overly smoky or even bitter in newer barrels,” he explains, adding that he does play with newer barrels for “perfuming the wine.” This is when small amounts of wine are added to new barrels, imparting a clean, white-smoke aroma from the char and rustic texture from the new oak—this wine alone would be too intense to drink, but when small quantities are added to the overall wine blend, it adds a subtle and appealing aromatic note.
Ménage à Trois uses barrels from its sister brand, Amador Whiskey Co. Once Amador’s Double Barrel bourbon is finished aging in new American oak, Ménage à Trois’s cabernet sauvignon is added to the still-wet casks for 3 months of aging. “New char is just too aggressive,” Andrade says. “We’ve found that the nuances of our various Amador whiskey mashbills add complexity to the wine that we otherwise wouldn’t get from new charred oak.”
Stephen Carroll, founder of Don Papa rum, works with a supplier out of Louisville, Kentucky to source bourbon barrels for aging. “We use other barrel types as well, but from our perspective, the bourbon casks dominate in terms of creating a product with deep flavor and a smooth mouthfeel,” he says. “We’ve also purchased some virgin American oak and placed rum in them, evaluating the liquid in these barrels every three to six months to see how they’re progressing. At the moment, our verdict is that it still needs more time. We’ll see how this continues to develop.”
American oak introduces aromas and flavor notes of vanilla, toffee, butterscotch, and hazelnut, which integrates well with a variety of spirits, including rum, tequila, and gin, as well as wine.
Novo Fogo sources bourbon barrels from Four Roses and Heaven Hill, and has a cooper in Brazil sand and re-toast them. “The cooper shaves off the char and some of the bourbon that has soaked into the wood and re-toasts the wood to a variety of levels—this is because in the hot, humid climate of Morretes, Brazil, the ‘devil’s cut’ of bourbon that has soaked into the wood would leach into our cachaça, making for a far more bourbon-y spirit than we desire,” McKinley explains. “What’s cool is that, unlike bourbon producers, we can fill barrels with cachaça over and over again until the oak has very little left to give to the liquid. Even then, our cooper can shave and toast the staves to give new life to a very old barrel.”
Although the use of bourbon barrels for aging and finishing is most common, it’s not unheard of to age other spirits in new American oak. “We use new American oak barrels, which we purchase from Independent Stave Company, for a couple reasons,” says Andrew Auwerda, president and founder of Philadelphia Distilling, producer of Bluecoat Barrel Finished gin. “First, we want to capture the same big flavors from the wood that bourbon gets, and using new charred barrels means we get first crack at extracting the vanillin, sugar, lactones, and all of the other flavors generated in that wood during the barrel raising. And second, using new barrels also means that there’s no other spirit’s influence on our product.”
Espolòn Tequila similarly uses new American oak barrels for all of its aged expressions, with its Añejo finished in Wild Turkey barrels for the best of both worlds. “New barrels contribute better to the flavor profile we’re seeking, whereas used barrels would be slower to change the flavor profile and the bourbon would add different notes,” says Espolòn’s global brand ambassador Angel Delgado. “For our aged expressions, we transfer the liquid into #2 char American oak barrels at a relatively low alcohol by volume, which means less water gets added before bottling, to lock in more of that pure tequila flavor.”