Jeff Stringer, PhD, the chair of the Department of Forestry and Natural Resources at the University of Kentucky, annually tracks wood commodity prices. Around 2012, he noticed a significant increase in demand for a specific product: white oak staves. These thin strips of wood are used as the foundation for barrels in which bourbon, whiskey, and other spirits are aged.
In the past decade, the bourbon and whiskey industry has experienced significant growth, resulting in an increased demand for white oak barrels. To qualify as bourbon, a spirit must be aged in a new, charred oak barrel. Many distillers prefer white oak for two reasons. First, it imparts flavor to the spirit. Second, it is practical since white oak doesn’t leak.
Greg Roshkowski, vice president and director of wood planning, procurement, and processing for Brown-Forman, explains, “The barrel provides both the color and over half of the flavor of the whiskey. The complex sugars in white oak break down during the aging process, allowing the whiskey to develop its sweet caramel flavors. Other hardwoods, like red oak, lack the tylosis membrane present in white oak and would leak extensively if used for barrels.”
Roshkowski estimates that the bourbon industry utilizes about 10% of the total annual white oak harvest in the United States.
Aged Oak Barrels
Brown-Forman consumes approximately 40-50 million board feet of white oak lumber each year to produce around 800,000-900,000 barrels for brands such as Woodford Reserve, Jack Daniel’s, Old Forester, and others.
The demand for white oak is equally high at Buffalo Trace Distillery, where they produce bourbon brands such as Buffalo Trace, Blanton’s, W.L. Weller, and Van Winkle.
Elizabeth Wise, senior vice president of government affairs for Sazerac, the parent company of Buffalo Trace Distillery, says, “We are currently constructing a new warehouse every four months, and we plan to continue doing so in the foreseeable future. Each warehouse can hold 58,000 barrels.”
White oak trees are typically harvested when they are between 80 and 100 years old. However, since the 1980s, foresters like Stringer have observed that American white oak forests are not regenerating robustly. To ensure a sustainable supply of white oak for the spirits industry and other industries relying on this wood, such as flooring and cabinet-making, changes needed to be made.
This led to the establishment of the White Oak Initiative in 2017.
Protecting Forests of the Future
The White Oak Initiative, spearheaded by Stringer, the American Forest Foundation, and DendriFund (Brown-Forman’s independent sustainability-focused foundation), now includes various forestry management and spirits industry partners.
Their mission is to ensure the survival and growth of American white oak forests through targeted forestry management and replanting when necessary. The initiative provides educational workshops on best practices for foresters and landowners. These workshops outline strategies for selectively clearing competing tree species in forests to allow white oaks to regenerate naturally.
Stringer and his fellow researchers are developing white oak cultivars resistant to insects and other challenges, as well as methods to improve stave manufacturing yields to reduce wood waste during barrel production.
Most bourbon barrels consist of approximately 31-33 white oak staves bound by steel hoops and rivets. The barrels are charred for flavor before being filled with spirits. The liquid is then aged in the barrels for a minimum of two to four years, often longer for premium labels, before being bottled. According to law, bourbon barrels can only be used once for distillation, so Kentucky distillers frequently ship used barrels nationally and internationally for aging other liquors, including Scotch, tequila, rum, certain wines, and craft beers.
Given the crucial role barrels play in bourbon and whiskey production, industry executives recognize the importance of securing a long-term supply of white oak for the future of their products.
Elizabeth Wise states, “Sazerac and other industry members involved in the White Oak Initiative understand that the bourbon industry must focus on replenishing one of its most critical assets for our survival. The White Oak Initiative is about the long-term sustainability of America’s white oak forests.”
Barbara Hurt, executive director of DendriFund and a fifth-generation member of the Brown family, agrees. The spirits industry’s commitment to white oak sustainability contributes to a larger cause beyond whiskey alone.
Hurt says, “We believe that environmental challenges can only be resolved with businesses actively participating. Industry plays a vital role. This initiative presents a tremendous opportunity to bring together individuals and organizations dependent on white oak.”
The implications are far-reaching.
“It’s not just about bourbon,” she adds. “When managing for white oak, you’re actually promoting the overall well-being of the forest ecosystem, benefiting wildlife, ecology, and our communities.”