Terroir: definition 

The terroir is made up of all the factors of the vine ecosystem: soil, subsoil,

climate and topography, and also the person who makes the wine: the winemaker.

Soil

The soil should be poor but balanced. The roots of the vine draw water and nutrients from the soil, the nature of the  soil and the trace elements it contains as well as its water regulation therefore contribute to the taste of the wine.

Climate

The climate determines the growth and ripening of the grapes. All its components are therefore part of the elaboration of the terroir: rainfall, winds, sunshine and temperatures. The key to a terroir is its water balance, which is generally deficient or weakly positive.

Topography

Hillside soils are, as a rule, poorer than lowland soils, so the vines are less vigorous, the yield lower, but of higher quality.

The winemaker

The intervention of the winemaker also plays an important role since it is he who determines the choice of cultivated plots, takes care of the soil, chooses the best period for the harvest.

Types of soils

The type of soil seems to induce characteristics:

• siliceous soils promote finesse, subtle and floral
• notesclay gives 'harder', firmer, powerful and alcoholic wines, aromatic polyphenols
• limestone induces roundness, suppleness, mineral, floral and fruity notes.

Terroir: a system of interactions

It is necessary to distinguish the Agro-terroir from the Socio-terroir.

The first brings together all the physical factors of the environment and the second, the human factors; but all these biological factors interact with each other.

The wine landscape is the visible and legible part of a terroir and a territory. The landscape will give a tone to the wine.

The features of the Saint-Estèphe Terroir

One of the main characteristics of the Saint-Estèphe terroir is the presence of deep layers of clay which protect the vines from hydric stress in very dry years. Another characteristic of the terroir is the presence of a marine limestone (known as ‘Saint-Estèphe’ limestone) in certain parts of the appellation. The diverse soil composition, its interaction with the climate and the balance in the subsoils are what gives the Saint-Estèphe terroir its subtle yet complex character.

Recent alluvium
palus

Oligocene limestones
with asterias

Sandy
colluvium

Oligocene
marls and clays

Terrace 5
sandy gravels

Ecocene limestones
of St Estèphe

Terrace 4
clayey gravel

Terrace 3
gravels

The genesis of the terroir of St Estèphe

Through a short film that is both fun and educational, the Saint-Estèphe appellation wished to show the formation of its terroir with the geological variety of the soil and the subsoil unique in any the Medoc peninsula.
Intended for all audiences, both professionals and amateurs, this film in 3D aims to understand the geological history and climate, that of the gravel terraces deposited over the millennia by the river on the limestone base of Saint-Estèphe which today constitute the favorite terroir of his vineyard.

Watch the film in its entirety at the Maison du Vin de Saint-Estèphe from Monday to Friday from 10 a.m. to 6 p.m. and Saturday from 2 p.m. to 6 p.m.