Where do bourbon barrels come from? And where do they go when their primary job of aging bourbon is complete? Most US distilleries get their barrels from the Independent Stave Company (ISC), headquartered in Missouri with their primary cooperage, the facility used to craft barrels, in Lebanon, Kentucky. ISC is a fourth generation family owned company and the largest maker of bourbon barrels in the world. The wood used to make their barrels is American white oak originating in Missouri. White oak is used for it’s durability and strength as well as the many complex flavors it can add to the distilled spirits aged inside. These barrels are hand-crafted by expert “Coopers”, a profession dating back to the 1800’s.
Once the oak tree is harvested, the lumber is cut into barrel length sections and then into “staves”. These staves are stacked and “seasoned” by leaving them outdoors through summer and winter. The staves are then hand selected by the cooper to form each barrel. Staves are not all the same width, requiring special skill and attention to form the perfect barrel. Once assembled the 53 gallon barrel is then charred using an open flame. The amount of char varies from a level 1, the lightest char, to a level 7, the heaviest char, and is specified by the distiller. The most common level I’ve seen used by Kentucky distillers is a level 4, also known as an “alligator char” due to the resemblance to the animal’s skin. The charring process caramelizes the natural sugars in the wood which contributes to the bourbon’s color and flavor. The final metal hoops are then applied to help the barrel keep its shape and minimize leaking. It’s important to note that no glue, screws, or nails are used in the final barrel as this would affect the flavor of the spirit aging inside.
The widest stave in the assembled barrel is located and a bung hole drilled. This specific location is chosen by the cooper due to it’s strength. The bung hole will be the weakest point in the barrel, the widest stave will provide the highest strength. The bung hole will be used to fill and empty the barrel as the ends will be sealed. Finally, the barrel is pressure tested and inspected for quality. Now the barrel is ready to be shipped to distilleries around the world and used to age the bourbon we love.
The barrels can only be used a single time to age bourbon. So what happens to the barrels after their life aging bourbon? Just because they can’t be used again for bourbon doesn’t mean they can’t be used to age other spirits. Many former bourbon barrels are used to age scotch or beer. Some distilleries will re-use their own barrels, others will sell them. Town Branch distillery uses theirs for the popular Kentucky Bourbon Barrel Ale, and I’m told may be using them at their upcoming scotch distillery.
Bourbon barrels have a long and rich history. I hope you enjoyed this glimpse into the process, thought, and craftsmanship that goes into each one.