All of the barrels used in the Campo Azul aging process were previously used to mature at least 8 years of American bourbon or whiskey. These barrels are constructed of American white oak, and we repair them before using them at Campo Azul to get the finest results. The aged Campo Azul (reposado) is aged for 8 months, while the extra-aged Campo Azul (aejo) is matured for 14 months.