Throughout the past century, if you asked a wine lover to associate a word with "Spanish red wine," the likely response was "Rioja." But those days are over, and today the same question might well draw a response of Priorat or Toro or Ribera del Duero. Rioja's once-incontestable primacy is now being challenged by each of these three regions, and other regions are looking to get into the race as well.

Quality is rising at remarkable rates across Spain, and there is no question that competition will intensify in coming years. How Rioja will respond is in part an open question, as the outcome will be dictated by consumer preferences that are impossible to predict. However, the nature of Rioja's response in terms of viticulture and winemaking is already becoming clear. This is partly because responsive strategies are always formed in part by the shape of the threat, and in Rioja's case the threat is obvious: wines from elsewhere in Spain -- and from the world beyond -- that are darker, denser, riper and more deeply flavored than typical Riojas.

On the basis of interviews and tastings conducted at 18 bodegas in July, as well as another round of tastings conducted recently back here, I'd say we've now got a good idea of what Rioja can do about this threat. Recent releases reveal Riojas that are becoming darker, denser and deeper before our eyes, and the trend is too widespread to be ascribed merely to the outstanding 2001 vintage.

In Rioja's vineyards, this has been accomplished by planting vine clones that produce fewer but more concentrated grapes, grafting onto rootstocks that further lighten crop loads, pruning more aggressively so that vines set fewer clusters in spring, dropping fruit during the growing season, and waiting for the remaining clusters to get riper before harvesting in autumn. In wineries, sorting tables are being used to select fruit more rigorously. Macerations are running longer and fermentations are running hotter to extract more color and flavor. Old oak casks are being replaced with smaller, newer barriques, and bottling is occurring earlier to capture fruit flavors prior to oxidation.

How competitive are the resulting wines? On balance, they are competitive indeed. Even after the exercise progam I've just summarized, they still don't show as much muscle as comparably priced wines from Toro, Ribera del Duero or Priorat. But in general they show a little more complexity and food-pairing versatility than any of these three.

Whether that is enough to keep them ahead of their main competitors will be for you to judge. The issue cannot be settled in the abstract, since it would be as foolish to say flatly that bigger is better in wine as to say that veal is simply inferior to beef because it isn't as dark or robust. Size matters, but so does sophistication.

In sum, thanks to the effects of keen competition in Spain, the crop of Riojas currently available here is the best I've ever tasted. Top wines from my recent tastings are listed in order of preference, with importers and approximate prices indicated in parentheses:

OUTSTANDING

Guzman Aldazabal "Exaltacion" 2001 ($90, Grapes of Spain): This stunning, thoroughly modern Rioja combines impressive darkness and density with very ripe, open fruit and remarkably soft texture. Intense in flavor but gentle in feel, it is an exemplar for the future.

Muga "Torre Muga" 2000 ($70, Ordonez): A superb wine with deeply flavored black cherry fruit balanced against lots of spicy oak. Although it will develop additional complexity for another decade, it is ready now with food.

Finca Valpiedra Reserva 1997 ($33, CIV): This is a marvelously intricate wine, with moderate weight but very full and complex flavors as well as fantastic aromas of black raspberries, wood smoke, tobacco and leather.

Pujanza "Norte" 2001 ($75, Grapes of Spain): This was hard and unexpressive when first opened, but over the course of 24 hours, it opened to reveal increasingly complex aromas and marvelously deep fruit flavors that are well tuned to the spicy wood notes.

Remelluri 2000 ($30, Ordonez): This is a marvel of integrated complexity, with explosive aromas of blackberries, fresh meat, tobacco and wood smoke. Medium-bodied, it is soft but adequately structured and culminates in a long, lovely finish.

San Vicente Tempranillo 1999 ($30, Ordonez): There is a lot of muscular, concentrated fruit in this bottle, along with hefty doses of spicy oak and ripe tannin. With a little patience, this will pay delicious dividends.

Dominio de Conte (Bodegas Breton) 1998 ($30, Classical Wines): Mature, complex and nearing its peak while showing no signs of drying, this features delicious black cherry fruit accented by well-integrated wood and lots of interesting little nuances.

Baron de Ona Reserva 1997 ($26, Europvin): Intensely aromatic, with dark berry fruit augmented by notes of wood smoke, with nice little spicy edging.

Miguel Merino Reserva 1995 ($30, Frontier): Perfectly mature and thoroughly delicious, this is also an excellent value. Soft, sweet and complex, it features an ideal balance between fresh fruit, smoky oak and secondary notes from bottle aging.

VERY GOOD

Muga Gran Reserva "Prado Enea" 1995 ($52, Ordonez): Delicious fruit recalling dried cherries, with accents of tobacco and spices.

Pujanza 2001 ($30, Grapes of Spain): Smoky wood notes and black cherry fruit notes, with lots of gutsy depth.

Sierra Cantabria Reserva 1999 ($22, Ordonez): Big flavors of dark fruits, with roasted, smoky aromas.

Ostatu Crianza 2001 ($18, De Maison): This total charmer is open, soft and pure, with expressive fruit and restrained oak.

Valsacro "Old Vines" 2000 ($28 Kysela): Rich and deeply flavored, with excellent concentration and balance.

Quertos Joven 2001 ($13, Grapes of Spain): Juicy, fleshy, flavorful stuff, with vivid fruit and almost no notable oak.

Coto de Imaz Reserva 1999 ($22, Wildman): Expressive aromas of dark berries and wood smoke, with fine balance.

Lorinon Crianza 2001 ($13, Classical Wines): Smoky, spicy wood is well tuned to the bright berry fruit here, with plenty of grip in the finish.

Valenciso Reserva 2000 ($34, Classical Wines): Pure, sweet cherry fruit notes are well integrated with fine-grained tannin.

Sierra Cantabria 2002 ($12, Ordonez): Gorgeously pure, expressive fruit leads the way, with a rounded texture and a long, soft finish.

Ramon Bilbao Tempranillo Reserva 1998 ($15, William Grant): A winning combination of sweet, fruity aromas and flavors with spicy, well-measured oak.

TASTY AND AFFORDABLE

Castroviejo Tempranillo 2001 ($11, Country Vintner); Faustino VII 2000 ($11, Palm Bay); Montebuena 2003 ($7, Kysela); Solarce Crianza 2001 ($11, Kysela); Rioja Vega 2003 ($6, Bacchus).

Michael Franz will offer additional recommendations and answer questions live today at noon on washingtonpost.com.