Until fairly recently, there were only three categories of tequila: blanco, which is unaged; reposado, barrel aged from two to 11 months; and añejo, barrel aged for one year or longer. As tequila ages, its color deepens and its flavors become more complex. Consequently, certain maestros tequileros (master distillers) keep a number of barrels aging far longer than the 12 months minimum required for an añejo. Over time, this practice became so widespread that finally, in March 2006, the Consejo Regulador del Tequila—the Mexican agency that regulates tequila production—established a fourth category for super-aged tequilas. This new extra-añejo classification was created for tequilas aged in oak barrels for three years or longer. While there is theoretically a point of diminishing returns in the aging process, these exceptionally aged tequilas have garnered significant attention in recent years. What follows are five of our favorite examples of extra-añejo tequilas, including three new releases.