🪨 Slate

Slate is a dark flat stone that splits easily into thin plates. It forms from clay compressed under pressure. Slate occurs on many slopes where grapes grow. Its look is familiar from roof tiles, but in a vineyard it serves as soil.

A special feature of slate soil is that the stone warms up in the sun by day and gives the heat back to the vine at night. This helps berries ripen in a cool climate. Slate drains water quickly and holds few nutrients, so the vine grows modestly and the berries come out concentrated. Roots go deep through cracks in the rock.

Slate is most famous in the valley of the Mosel in Germany: steep slopes covered with dark plates, and the Riesling that grows here. Slate is also found in the upper Middle Rhine valley and other areas. Wines from slate soils are often described as mineral, with fine acidity. Slate is one of the main soils in the world of wine.