Enrique Fonseca began experimenting with aging extra Añejo tequilas back in the early 2000's and not only varies the time the Tequila rests, but the types of barrels and altitudes in which they do so. From the traditional American and French oak barrels to used bourbon casks, or wine barrels, Enrique has created some of the most unique aged tequilas available. The Fuenteseca line starts at a minimum of 7 years and reaches all the way up to 21 years. Given that blue weber agave takes 8-10 years to mature to be used to make tequila, these expressions can take nearly 30 years to produce.