Castilla y León is located in North Central Spain, and was historically the seat of Spanish royalty during the renaissance. The most well known DO's of the area are Toro, Bierzo, Ribera del Duero, and Rueda.
Toro is an area that has changed its style of red wines from rustic and unrefined to what it is now-- powerfully rich and ripe. The main grapes known from this area is Tinto de Toro, which is the same grape as Tempranillo. Toro features very sandy soil. Because of this, and the large distance between vines, it remained largely immune to the harm of phyloxera.
Bierzo produces white wines mainly made from Godello, and red wines made from the Mencía. The soil in Bierzo has a large amount of slate, which gives a very mineral quality to the red wines especially. Most of the area is located at an altitude of approximately 3,000 feet, which allows the grapes to slowly ripen for a long time, adding complexity to the wine. This area is on the rise, and always attracting new talented winemakers due to the attractiveness of the growing conditions.
Ribera del Duero
As of this year, Ribero del Duero was elevated to a DOCa, putting it on par with Rioja and Priorato in terms of recognition. The area lies along the Duero river, which is the same river as the Douro that runs through the Port producing areas of Portugal. The soil of the area is sandy, with outcropping of limestone and chalk. During the day temperatures in the area can reach 100 degrees, but the nights usually remain very cool, which helps lend acidity to the wines. There is a danger of frost, but if the winemaker is attentive to this problem, the growing conditions can be ideal. Tinto Fino, yet another name for Tempranillo, is the primary grape here. For some reason, Ribera del Duero's recognition as a top wine producing area has come later than others, but the wines being produced their right now are indeed word class. The most receent 2004, 2005 and 2006 vintages were particularly outstanding, which has helped its reputation recently.
Rueda is now known for its production of Verdejo, a grape very similar in profile to Sauvignon Blanc. At one time, it was used to produce a sherry style wine. While the Moors ruled the area comprising Jerez, the main Sherry producing area, it was impossible to produce sherry there under Islamic law, so Rueda took over sherry production. When phylloxera hit Rueda, however, sherry production returned to Jerez. In the 1970's the Marque de Riscal decided that the limestone soils would produce a crisp, light, and dry white wine, which gave rise to the style of wine we know from Rueda today. There are three types of white wines produced in Rueda today. Rudeda Superior must contain at least 75% Verdejo. Another style is made of 100% Sauvignon Blanc, and Rueda Blanca must contain at least 40% Verdejo or Sauvignon Blanc. Rueda also produces sparkling wine, which does not fall under the Cava DO. Instead it is under the DO Rueda Espumoso. These wines are made mostly from the Verdejo grape as well.