The Grand Enclos de Las Cases is blessed with a very complex terroir. Mostly made up of Quaternary gravel on a sandy-gravelly and clayey-gravelly subsoil, we also find clays of varying depths and compactness, sometimes even outcropping. The proximity of the Gironde is responsible for this great diversity of soils, created over the geological periods by successive superimpositions. In addition, the river generates a very specific microclimate which allows the grapes to ripen very early and protects the vineyards from frost. This range of geological combinations influences the development of the vine and the constitution of the grapes. This incomparable terroir offers the great wine its unique personality.

The spring of 2006 was very cool, but the nice weather in May gave an even blossoming. July was marked by ten very hot days whereas August was rather cool and dry. The first ten days of September were also dry and hot and then there was a rainy period before picking. When it came to harvest-time the dry weather had however returned and allowed the crop to be picked in good conditions.