Rioja is Spain's most prestigious viticultural region, containing her oldest wine estates, partly a tribute to the Bordelaise who moved there in the late 1800s when phyloxera was ravaging France. Current figures indicate that as much as 40% of all Spanish wine exports to the US are Rioja reds. The Rioja region is situated in the far north of Spain, in Basque country. Despite its nearness to the ocean, Rioja is insulated from chilly maritime influences by mountain ranges. Coolness of vineyard site is largely governed by height above sea level. Rioja contains three sub regions, Rioja Alta, Rioja Alavesa, and Rioja Baja. The first two lie to the west of the region, while the latter, the hottest and driest of the three, occupies the eastern sector.

Tempranillo is the principal black grape of Rioja, although Garnacha is also widely planted, along with a number of other minor varieties. Although fruity nouveau style wines are produced in Rioja (Jovens), these are seldom seen outside the region. Rioja is more strongly associated with oak aged wines. The reason for this might be that Tempranillo is very resistant to oxidation, and would develop very slowly if traditionally vinified and bottled without some form of prior maturation in oak casks. Small American oak barrels are still the most favored maturation vessel, although French oak is also used by some bodegas (wine producers). The former often imparts a tell-tale sweet vanilla aroma.

Regulations stipulate the time that categories of wine must remain in cask: Crianza and Reserva wines spend one year minimum, while Gran Reserva spends a minimum of two years. The wine undergoes further mandatory aging in bottle or tank before being released: Crianza wines receive one year, Reserva wines two years, and Gran Reservas three years. Some estates may well exceed these minimums. All Rioja reds are in principal ready for drinking when released, but many of the best can be cellared for years longer, if not decades, a tribute as to how gracefully Tempranillo can age. Another useful consequence of extended barrel aging is that Rioja wines rarely throw any sediment in bottle, having already left their sediment in the barrel. Decanting is often not necessary.