Understanding the different types of soil in the vineyards
Soil directly and indisputably affects the wine and makes the terroir of a region, but it is easy to feel lost in the different types of soil. Petites Caves sheds light on this.
The soil is the support for the vine's roots, a reservoir of water and nutrients for the plant, more or less deep, more or less humid, and is the product of the alteration, reshaping and organisation of the upper layers of the earth's crust under the action of life, the atmosphere, temperatures and other energy exchanges that take place there. Its different soil types are determined by the nature of the subsoil (the unaltered parent rock) through physical and chemical alteration. Thus, on a calcareous and marly subsoil, the soils will be calcareous, clayey-limestone, clayey, marly; on granitic alterites, they will be sandy, siliceous, gravelly, stony; on alluvial gravel layers, they will be clayey-veleous, ... Do you have a headache? Let's look at it more precisely, in simpler language... and with pictures!
CLAY-LIMESTONE SOILS 
A slightly greasy earth, studded with white stones more or less hard. Balanced soils mixing clay and its freshness with the filtering properties of limestone. For example, these soils are perfectly suited to Merlot, grown in the Bordeaux region on the right bank of the Dordogne(Saint-Émilion, Fronsac, Côtes de Castillon). To discover the organic and natural wines of Bordeaux, click here.
CLAYEY-GRAVELLY SOILS
Clayey, brownish and somewhat heavy soils. Gravelly soils, of alluvial origin, can hide deep layers of more or less pure clay. Another example: Merlot and Cabernet Franc grow perfectly in these soils.
MARLY-LIMESTONE SOILS
The earth is ochre, strewn with white limestone and marly stones that are often friable. A very light terroir, the marls being nothing more than the combination of limestone and clay. Burgundy grape varieties (pinot noir and chardonnay for those who do not follow) flourish on this type of soil. In the glass, the clay of the marls often gives body and the limestone finesse.
For discover the organic and natural wines of Burgundy, click here.
CHALKY SOILS
An almost white earth with brown clay. Extremely porous and filtering, the chalk lets the water run off before retaining it in deeper layers to return it to the vine (a very good job, isn't it?) These apparently thin soils are therefore richer and more balanced than we imagine. Chardonnay in the Champagne region and Chenin in the Loire region have their place.
GRANITIC SOILS
Shallow, sandy soils resulting from the decomposition of granitic rocks. Gamay expresses itself well in the Beaujolais. Syrah(Hermitage, Saint-Joseph, Cornas, etc.) and Viognier(Condrieu) flourish in the northern Rhône valley.Alsace also has quality granite terroirs classified as Grand Cru.
GRAVELLY SOILS
Soils rich in pebbles that extend from the left bank of the Garonne to the Atlantic Ocean, and are the origin of the most prestigious crus of the Médoc and Graves. These pebbles brought by the Garonne and the Dordogne, mixed with sands and clays, form warm soils that allow the Cabernet Sauvignon to reach maturity.
ROLLED PEBBLE FLOORS
These soils have large, oblong, enormous, smooth stones, polished by the waters of the Rhone, in the southern part of the valley. Grenache expresses itself perfectly in these sun-warmed soils... even during the night because the stones reverberate the heat! To discover the organic and natural wines of the Rhône Valley, click here.
SCHIST SOILS
Soil types rich in more or less dark and shiny schist stones (schists, mica schists). Syrah produces in the northern Rhône valley the great Côte-Rôtie. In Languedoc and Roussillon, southern grape varieties such as Grenache or Carignan are grown on the schists around Faugères, Banyuls and Maury. These are still schist soils which give beautiful wines in Anjou based on chenin.
