The two basic categories of tequila are mixtos and 100% agave. Mixtos use no less than 51% agave, with other sugars making up the remainder. Mixtos use both glucose and fructose sugars.
Tequila is usually bottled in one of five categories:
Blanco [ˈblaŋko] (“white”) or plata [ˈplata] (“silver”)
White spirit, unaged and bottled or stored immediately after distillation, or aged less than two months in stainless steel or neutral oak barrels
Joven [ˈxoβen] (“young”) or oro [ˈoɾo] (“gold”)
Unaged Blanco tequila that is colored and flavored with caramel
Reposado [repoˈsaðo] (“rested”)
Aged a minimum of two months, but less than a year in oak barrels of any size
Añejo [aˈɲexo] (“aged” or “vintage”)
Aged a minimum of one year, but less than three years in small oak barrels
Extra Añejo (“extra aged” or “ultra aged”)
Aged a minimum of three years in oak barrels, this category was established in March 2006.
With 100% agave tequila, blanco or plata is harsher with the bold flavors of the distilled agave up front, while reposado and añejo are smoother, subtler, and more complex. As with other spirits aged in casks, tequila takes on the flavors of the wood, while the harshness of the alcohol mellows. The major flavor distinction with 100% agave tequila is the base ingredient, which is more vegetal than grain spirits (and often more complex).