Bright orange flames danced at the tip of the open-ended white oak barrels, then intensified until thick columns of fire roared through the center of the casks, turning the vault-like heart of the Brown-Forman Cooperage into a temporary inferno.
The so-called charring of the barrels plays a critical role in bourbon making. As the heat radiates outward, it effects physical changes in the wood that enhance the distillate’s color and flavor.
For example, the organic polymer lignin, when heated, breaks into vanillin, the primary component of the extract of the vanilla bean. More charring means more vanilla flavoring.
Another wood component, tannic acid, colors the bourbon. Depending on charring time, the acid turns the bourbon from a yellowish orange to a reddish brown.
And a cellulose material, hemicellulose, breaks into sugars when heated, adding flavors ranging from dark chocolate to butter scotch.
“You dial those up — flavor, color, aroma — by how you expose the wood to the heat,” Brown-Forman master distiller Chris Morris recently told IL during a tour of the cooperage.
The Brown-Forman Cooperage is celebrating its 70th anniversary this year, at a time of a bourbon resurgence. Domestic production of whiskey has risen 60 percent in the last decade, according to the U.S. Department of the Treasury. Last year, production rose nearly 4 percent, and production in January of this year was 27 percent higher than a year ago.
The cooperage building was constructed in 1922 as a furniture factory. During World War II, it produced rifle stocks for the British government. When the U.S. entered the war, it made wooden control surfaces for planes.
After the war, the owners put the plant up for sale. At the time, most large distillers had their own cooperage, Morris said. Brown-Forman, a medium-sized business at the time, did not, but Oswley Brown I saw the plant’s potential.
The cooperage made its first barrel in 1946; the company still owns the barrel head.
Today, Morris said, Brown-Forman is the world’s only major distiller to make all of its oak barrels.
The cooperage, which sits just west of the airport, produces about 2,500 barrels per day, in two shifts, or about 600,000 per year.
Years in the making
Outside of the cooperage building, 15-foot-high stacks of wood stretch into the distance. The wood remains outside for months, even years, before it is moved to giant, heated warehouses, or kilns, for a few more months to remove moisture. In the semi-darkness of the kilns, which are about twice as big as a football field, loud fans whir as they blow hot air over the planks.
Each brand has its own drying requirements. Wood for some of the bourbon remains in kilns for months.
Energy for the kilns is created by burning wood chips and sawdust that is collected in the cooperage, as planers and saws cut the wood into the stakes.
Each barrel is made out of 33 stakes, alternating between wide and narrow. After charring, the barrels cool before they are encased with the metal hoops. Employees drill a bung hole, through which they pour in a gallon of water to detect leaks. The barrels’ integrity is critical to preventing spillage of their precious contents: A cask of Woodford Reserve has a value of about $12,000.
“You don’t want these to leak,” Morris said wryly.
The barrels also have to last: Some of them age bourbon for 12 years. But they also have to be filled with the product as quickly as possible, because once the barrels dry out, they get brittle and begin to leak. As soon as the barrels have been put together in the cooperage, they get loaded onto trucks and are driven straight to the distilleries.
Brown-Forman has another cooperage, in Decatur, Ala., dedicated to Jack Daniel’s, and a used barrel cooperage in Lynchburg, Tenn. The company also owns stave mills in Alabama, Tennessee and, soon, in Spencer, Ind. The mills cut trees for the cooperages.
Wood comes only from one type of tree, quercus alba, or white oak, which grows as far south as northern Alabama and all up the Appalachian Mountains into New York and Pennsylvania, as well as in the Ozarks and north into Minnesota. Trees in the north grow more slowly, because they get less sunlight and have a shorter growing season. That changes the wood’s porosity and grain structure. While the tree’s flavor would be the same, the density would change how the barrel would breathe, Morris said. Barrels from Southern wood would see more oxidation, making their product fruitier, but for its barrels, the company combines woods from all areas.
Morris explained that owning its cooperage has allowed Brown-Forman to experiment with different types of wood, which independent cooperages cannot afford to do. As a result, Brown-Forman coopers have developed an unmatched expertise.
Andrew Faulkner, vice president of the American Distilling Institute, said owning its own cooperage also gives Brown-Forman greater control over the supply chain. That kind of control has been helpful since the bourbon business began to boom a few years ago.
Since 2009, domestic whiskey production has nearly doubled to 147 million proof gallons, while the flow of other distilled products — brandy, rum, vodka — has slowed.
Faulkner said the dynamics are starkly different from the 1970s, when vodka had grabbed the public’s attention and distillers were sitting on barrels of whisky they struggled to sell. After the slow food movement, craft cocktails made a comeback and piqued people’s interest in brown spirits, especially bourbons.
The higher demand for bourbon — and barrels — occurred at a time when many lumber mills had gone bankrupt after the housing market crashed, Faulkner said. And two years ago, a longer-than-normal rainy season in spring made roads into forests muddier and delayed lumber companies’ access to trees. The wood shortage made wood — and barrels — more expensive.
Years ago, a company bought bourbon from a bankrupt distiller for $450 a barrel, Faulkner said. “Now you can’t even get the barrel for (that.)”
Brown-Forman announced last summer it had acquired a mill in Spencer, Ind., near Bloomington, and would hire about 50 people to produce more staves for its cooperages, increasing capacity and reducing reliance on other mills.
Sense of pride
The company’s cooperage operation employs about 500, or about 11 percent of its total global workforce. Work in the cooperage takes a lot of skill, Morris said, especially the repairing of barrels that get damaged during production.
Employees have an average seniority of about 13 years, Morris said.
Michael Nelson, the cooperage plant director, said that keeping up with the industry boom has been a challenge — and a blessing.
The demand has meant longer days for some employees, including some work on Saturdays, but Nelson said cooperage employees take pride in their work, knowing their product has a significant impact on the company’s brands.
Nelson joined the cooperage about two years ago after working in the construction materials industry. He said that he, like many other cooperage employees, enjoy playing an important role in an industry that is steeped in Kentucky history.
“There’s nothing else out there like it,” he said.