Over the last 30 years, there has been a rise in single-vineyard Barolos, even as a few ardent traditionalists like Bartolo Mascarello insist on the primacy of wines blended from different communes. Similarly, in Champagne, where blending has been portrayed and marketed as an art form, more producers emphasize the terroir and the vineyard.

The same debate is occurring in Rioja, as many people believe the aging requirements offer no assurances of style or quality. Exacerbating the debate, said Víctor de la Serna, who writes about wine for El Mundo and is a co-author of “The Finest Wines of Rioja and Northwest Spain,” is what he calls Rioja’s “headlong plunge into mass production of ever cheaper wine.”

The rise of cheap industrial Rioja, Mr. de la Serna said, affects the entire market, including the gran reserva category.

“The problem is that anyone can get a gran reserva back label if they age the wine following the rule book, and even in that category, price differences can be huge,” he said, citing a 2010 gran reserva from Campo Viejo selling online in Spain for around $13 (in New York, the wine sells for around $20). Prices like that, he said, make it difficult for more quality-minded producers to sell their wines for the higher prices that they need to maintain their standards.

Many top producers are pushing the regional wine authorities to enforce higher quality standards for Rioja as well as to create geographical subdivisions, like Burgundy’s hierarchy of regional, village, premier cru and grand cru wines. Last year, more than 150 Spanish wine professionals, in a meeting organized by Telmo Rodríguez of Remelluri, signed a manifesto urging wine authorities to create such hierarchical classifications for Spanish wine regions.

Mr. de la Serna was among the signers, though he doesn’t hold out much hope for it.

“I’m very skeptical of such an approach ever being reality,” he said. “This is Spain, after all, and wine culture seldom forms the basis of wine regulations.”

María José López de Heredia, who, with her sister, Mercedes, and brother, Julio César, runs the winery founded by her great-grandfather, said in an email that classifying a wine, whether by terroir, aging requirements or production methods, will not assure that it is good.