Which spirit is most likely to age in oak barrels?

Cognac is the spirit most likely to age in oak barrels due to its production methods and the legal regulations surrounding it. As a type of brandy made from distilled white wine, Cognac must be aged in wooden casks, specifically oak barrels, for a minimum of two years to develop its complex flavors and aromas. The interaction with the wood during aging imparts vanillin, tannins, and other flavor compounds, enhancing the overall profile of the spirit.

In contrast, gin is typically flavored with botanicals and is not generally aged, while vodka is usually produced in a manner that prioritizes purity and smoothness, resulting in minimal to no aging. Tequila can age in oak, but the practices vary significantly, and it is not as universally required or defined as it is for Cognac. Thus, the aging process and requirements for Cognac make it the clear choice among the options provided.