It?s this formula that inspired former Vega Sicilia winemaker Xavier Aus?s to claim Ribera del Duero as ?the best? region in the world for red wines. ?This region is a 10,? said Aus?s several years ago during my previous visit to Ribera del Duero (RDD), which lies in the heart of the autonomous community of Castilla y Le?n. ?If someone is making a wine here that rates a 5, that person is delinquent.?