The Spanish Oak Bourbon saw the distillery's bourbon matured with oak staves that were harvested from the forests of northern Spain and seasoned outdoors. The distillery said this European oak maturation has yielded a drier, spicier whisky with more wood influence than traditional maturation in American white oak casks.
It is the fifth expression in the Old Charter Oak range, following Chinkapin Oak, Mongolian Oak, French Oak, and Canadian Oak releases.
Harlen Wheatley, Buffalo Trace master distiller, said: "The whiskey extracts from the charred oak barrel, exciting elements like eugenol, vanillin and whiskey lactone.
"American oak has higher proportions of vanillin and whiskey lactone, resulting in bourbon with a softer, sweeter taste and notes of vanilla and caramel. Our Spanish oak, on the other hand, has more eugenol, meaning drier, spicier notes and flavours like clove are imparted to the liquid.
"We specifically wanted to test Spanish oak as part of this collection because of its connection to sherry, which is known to be a nuttier, fruitier spirit. We were curious how those flavours would impact the taste of whiskey, and we are very pleased with the result."
Wheatley said one aim of the Old Charter Oak collection was the challenge the misconception that bourbon must be aged in American oak barrels – while these are the most common bourbon maturation vessels, federal regulations only state that the container must be made from new oak and be charred, giving no geographical constraints on the oak's origin.
"At Buffalo Trace Distillery, we are deeply committed to honouring the traditions of our category but also embracing change and pushing the limits of innovation to see where American whiskey can go in the future. Our Old Charter Oak collection is a superb example of trying new things and offering consumers and fans more ways to enjoy our award-winning portfolio of whiskeys," Wheatley said.
Packaging for Spanish Oak will remain consistent with the collection's other releases: a glass bottle with a cork finish, adorned with an oak medallion depicting the Charter Oak tree. Buffalo Trace Spanish Oak Bourbon will be available in select markets in the US from spring 2023 with a suggested retail price of US$69.99 per 750ml bottle.