The vineyards of Ribeauvillé are located in a large area of geological fractures. There is a main network of fault-lines running North-South, crossing smaller ones running East-West, and there have been periodic tectonic collapses, all of which have combined to create distinct geological strata.
These have brought about a structure comprising clearly split-up geological compartments (in other words a structure like a mosaique).The compartments consist of hard limestone, clay and marl from the Liassic and Triassic periods, sandstone clay, and chalky calcareous conglomerates from the Oligocene epoch.
In the valley and across the plain there are also silt-laden deposits from the Triassic period, and sandy or stony glacis and alluvions.
The microclimate of Ribeauvillé is characterised by its low rainfall - between 550 mm and 650 mm per year. One small chalky hill in the north of the vineyard is even home to the green lizard, a Mediterranean species.
In the spring one also sees the blooms of species of orchid typical of dry calcareous hills.
In summer the days are hot. At night, however, temperate winds emerge from the valley to cool the atmosphere. This temperature alternation favours the development of fine and delicate aromas, particularly in the Gewurztraminer species of grape.
In autumn, mists form on the plain above the Fecht and Ill rivers, which are conducive to what is known as the "noble rot", a process necessary for the late harvest wines ("Vendanges Tardives") and the superior grape selection wines ("Sélections de Grains Nobles").
The quality of Ribeauvillé's soils has been recognised by the INAO, the organisation which oversees all label-of-origin wines ("Appelation d'Origine Contrôlée" or "AOC"). In fact we are fortunate enough to have three wine-growing areas on the edges of Ribeauvillé community district which merit the class of "Grand Crus" : Kirchberg, Geisberg and Osterberg.