The dominant red grape in Bierzo is the Mencía, although Garnacha Tintorera, Tempranillo and a few other grapes are also used to make Bierzo's red wines. Native whites include Godello, Palomino, Doña Blanca and Malvasio. Of all these, it's the Mencía that has been driving recent interest in the wines of Bierzo. The grape is cultivated almost exclusively in the north of Spain, and its flavor is reliably unique -- fruity, tannic but not harsh, with mineral notes [source: Cellar Tours]
Though it focuses on native grapes, Bierzo's viticulture is somewhat continental. Mountains protect the low-lying region from the ocean-driven extremes of temperature that threaten the rest of Spain. Much of the soil is or was once alluvial; centuries ago, the area used to be a lake [source: Parode]. Fertile alluvial soils still line the Sil River.
Higher, in the steep, rocky slopes, soils are chiefly slate with a high mineral content, and the temperature and climate are more like those of France than of the rest of Spain [source: Cellar Tours]. Soil in some areas contains quartzite, a further defense against high temperatures. Alvaro Palacios swears that wines reflect the flavors of wild local herbs such as jara (both citrusy and warmly spicy). Elm and chestnut trees dot the hills, and lush green ivy clings to the walls and rocks [source: Schoenfeld].
Bierzo combines hot days with cool nights -- a combination widely believed to be key to the development of strong, intricate flavors in wine. Sugars develop in the daytime heat, which can reach 105 degrees Fahrenheit (40.5 degrees Celsius). But when that heat is regularly interrupted, the sugars become nuanced rather than overwhelming [source: Schoenfeld].
Aspects of Bierzo will make you feel as though you've traveled backwards in time. Some villages still have communal bread ovens and laundry pools, and many people still live in small, centuries-old stone houses. Likewise, most vineyards in Bierzo are relatively small operations -- family-owned tracts of about 2 acres (.8 hectares). Because the mountains are so steep, cultivation and harvesting still rely on horses and mules [source: Apstein]. Outputs are therefore fairly low. For economic survival, many growers have come to rely on cooperatives.
On the next page, we'll take a look at the wines that are beginning to draw so much international attention.