Limestone subsoil

The subsoil in Champagne is predominantly limestone. So too are the outcrops of sedimentary rock (75% limestone), composed of chalk, marl and limestone proper. This type of subsoil provides good drainage and also imparts that particular mineral flavour found in certain Champagne wines.

Regional differences in subsoil

• The Côte des Blancs, the Côte de Sézanne and Vitry-le-François lie on an outcrop of chalk.
• The  Montagne de Reims lies on a deep bed of chalk.
• The Marne Valley (west of Châtillon-sur-Marne) and the hills around Reims (Massif de Saint-Thierry, Ardre Valley and Montagne Ouest) lie on soils containing more marls, sand or clay.
• The Côte des Bar (Bar-sur-Aube and Bar-sur-Seine) lies on soils essentially derived from marl.

The magic of Champagne chalk

The chalk in Champagne consists of   granules of calcite formed from the fragile shells of marine micro-organisms (mainly coccolites). Being highly porous, it acts as a reservoir (storing 300-400 litres of water per m3, or 79-105 US gallons) that provides the vines with a steady supply of water even in the driest summers.

Chalk draws in water through capillary action. The effort required to tap into this water supply puts the vines under just enough water stress in the growing season to achieve that delicate balance of ripeness, acidity and berry aroma potential.