Spain’s picturesque Ribera del Duero wine region, one of the nation’s leading producers of fine vintages, is located on a high plain that brackets the Douro River. The rich farmlands run for 71 miles through the provinces of Soria, Burgos, Segovia, and Valladolid in the autonomía, or state, of Castilla y León, north of Madrid. Archaeological evidence suggests wine has been made here for 2,600 years, since the Romans commanded these lands, and the geology explains why. The vineyards sit at 2,500 to 3,600 feet above sea level, and such high altitudes provide what’s known in viticulture as the diurnal temperature shift: Hot, sunny summer days offer ideal conditions for grapes to ripen, while significantly cooler nights allow them to retain their freshness and acidity.
Locals call Tempranillo, the main…