Terroir and characteristics of the wines of Alsace

The hillsides of Alsace

The best terroirs in Alsace are located on the ridges by the foothills of the Voges, between two geological faults. Here, the bedrock is a mosaic of cracks and disruptions in many directions. On top of the bedrock, soils of varying origin form a thin layer that has either has been formed on site, as alluvium or moved by gravity from higher elevations.

The heading photograph shows how the "fingers" connecting the granitic mountain range and the plain are shaped. The picture is taken from north to south from above Kientzheim, showing the village Ammerschwihr. In fact, the photo is taken from th edge of Grand Cru Furstentum, showing Grand Cru Kaefferkopf.

The upper parts of the hillsides are granitic, normally followed by Bundsandstein, Muschelkalk and marl of various origin. Here and there, for example on Grand Crus Altenberg de Bergheim and Florimont (Ingersheim) oolitic Jurassic limestone dominates, but this is quite rare.

The plain on the picture consists of alluvium deposited by the river Weiss during Quartenary.

The map below shows the most reputed section of the heart of Alsace. On the map, Crand Crus of similar geological character are shown in a certain color.

On bedrock from Triassic and Jurassic, one can separate the Grands Crus into three classes; limestone, an intermediate group and terroirs low in lime. The rule of thumb is that the higher the lime content, the more acidity is brought to the wine. If the acid content is high, the grapes may be harvested quite late which gives a good chance of making a wine that combines body, complexity and storage potential.

The map is taken from the magazine Munskänken 06/2004. Created by Ulf Jansson (artwork) and Per Warfvinge (idea). Legend: Östlig förkastning = Eastern fault, Västlig förkastning = Western fault,