Soils are composed of varying proportions of bedrock formed by erosion at the site, materials transported by gravity, wind, water, or glacial activity, and organic matter deposited on the ground or transported by similar means to other materials. The soils overlie the bedrock.
Clay is composed of the smallest particles, followed by silt, sand and gravel. Red wine grapes benefit from a high proportion of clay in the soil because the small particle size is ideal for nutrient and water uptake by small roots, but if the particles are too small, they can smother the plant. This ease of reaching nutrients allows the plant to develop the phenolic compounds in the grape skins that will later give the wine color, aroma and texture.
Thanks to their texture, they are the most suitable soil for vine growing, as they facilitate the permeability and drainage of the vine.
Another beneficial feature is that the light color of the pebbles reflects the sunlight, which helps to regulate the temperature of the plant. Also, be aware that there is less surface moisture because the surface water comes from a well.
This soil requires little water, which saves watering the vines. In addition, it allows the plant to ripen in less time. The wines obtained are generally sweet and low in alcohol.
The solid and more or less uniform rocky soils allow the plant to reach a progressive maturation, not very fast. Its wines are characterized by an aromatic and clear flavor.
These soils have little organic matter and do not allow the roots to penetrate very deeply into the earth. Another characteristic is that, by reflecting the sun's heat, they help the vines reach maturity earlier. They produce wines with higher alcohol content, mineral aromas and a complex taste.