What type of liquor is typically aged for a minimum of three years in oak barrels?

Scotch is typically aged for a minimum of three years in oak barrels, which contributes significantly to its flavor profile and character. During this aging process, the interaction between the spirit and the wood of the barrel leads to a series of chemical changes, allowing the whisky to develop complexity, depth, and a range of flavors that can include notes of vanilla, spice, fruit, and oak. This maturation is essential for Scotch, as it must adhere to strict legal requirements that define what constitutes Scotch whisky, including the aging period.

Other types of liquor, such as tequila and rum, can also be aged, but their aging requirements differ. Vodka, on the other hand, is generally not aged at all, as it is intended to maintain a clean, neutral flavor. Therefore, Scotch's specific requirement for a minimum of three years in oak barrels makes it the correct answer to this question.