In general terms, it can be said that the Bierzo is made up of two different types of soils: one basically of sandy soil situated around the area in the exterior side of the “Hoya”; the other precisely making up the tectonic pit of Central Bierzo.
This soil is composed of clayish materials, although this area presents a clear undifferentiated characteristic which has developed as of a Continental type substratum with clay, sand and alluvial deposits of the Tertiary and Quaternary Eras.

The basic components making up the exterior sandy soils belong to the Primary Era and are composed of quartzites, sandstone, slate and limestone. On the other hand, the different types making up the interior clayish area contain various types of clay and sands including a great quantity of smooth edges. As far as heights of over 700 metres are concerned, we can find skeletic soils which have developed into Ranker type, humid soils in the Hoya.

The Ranker has been changing to produce brownish soils. These soils, together with the climatic conditions in the Bierzo region, have allowed the formation of rich agricultural soils, especially in the Hoya of El Bierzo.