🪨 Chalk

Chalk is a soft white limestone. It consists of the remains of tiny marine organisms that lived in ancient seas. Chalk holds water like a sponge and gives it to the vine in a dry summer. It is also cool, and its pale surface reflects sunlight.

The most famous example is Champagne in north-eastern France. The slopes of Champagne rest on a chalk base. Chalk gives sparkling wine freshness and a lean build. Underground cellars have been dug in the soft rock, where bottles of Champagne mature at a steady temperature. They are known as the chalk cellars of Champagne.

White soil is known in Spain too. In the Jerez area it is called albariza: it contains a lot of chalk, and Palomino for sherry grows on it. In summer the top layer hardens and keeps the moisture in.

Chalk is a kind of limestone, but it is softer and more porous. Vines on chalky soils need rootstocks that tolerate lime.