American white oak—aka Quercus alba—is an integral part of whiskey today. This stately tree is used for the vast majority of both bourbon and rye casks, lending important vanilla and spice notes to the spirit. After being used to age these whiskeys, the barrels continue to spread the influence of American oak around the world, lending their properties to scotch, rum, tequila, and other spirits as well as wine and beer.
The ubiquity of Quercus alba casks is partly due to the vast number of trees available to cooperages. Huge stands of the mighty oaks stretch from Minnesota south to East Texas, all across the South, and up to New England. American oak grows in snowy plains, sun-soaked swamps, and ancient mountain forests. The wood from these trees is often treated as a single material without any differences or variation. But with such a diverse array of growing conditions, distillers must ask: Is all American oak created equal?
Oak’s Contribution
Oak is undeniably important to whiskey, and this is especially true for American whiskeys such as bourbon and rye, which require new, unused barrels. Virgin wood can have much more impact than a used barrel, and the oak is responsible for much of whiskey’s flavor. The federal rules that define bourbon and rye say they must use “charred new oak containers,” but they don’t specify that the oak must be American—yet virtually all these barrels are made from Quercus alba.