Bordeaux’s climate is special. It is moderated by the influence of the Atlantic Ocean which creates a maritime climate, with moderate winters and warm but variable summers. As a result Bordeaux experiences significant vintage variation. The vines benefit from the Gulf Stream and the protective warming effect of the Gironde Estuary which splits into the Garonne Left-bank (Medoc, Margaux) and the Dordogne Right-Bank (St.Emilion, Pomerol).
A history of terroir
245 million years ago France was under a shallow tropical sea. When the tectonic plates underneath the surface started to shift the area underwent turbulent geographic activity and the calcium rich shells of dead sea creatures created the limestone rich soils that we see in the Paris basin. Millions of years later the Gallo Romans excavated this limestone to use for their monuments and buildings, keeping them warm in the winter and cool in the summer. This limestone provides a similar effect for the roots of the grape vines.
Up until the 17th century the Medoc was swampy marshland, when Dutch engineers drained the water uncovering the rocky mounds of gravel and mineral rich soils treasured today.
The left bank is closer to the ocean and the soil is predominately a mixture of gravel with subsoil of clay. This gravel helps heat the late ripening and thick skinned Cabernet Sauvignon grapes, which otherwise could not ripen. On the Right-Bank in St-Emilion, further away from the moderating influence of the Atlantic the soil is predominately limestone, which is famed for retaining balanced amounts of water and providing an even uptake to the roots. In Pomerol clay dominates, which also easily absorbs water, keeping the vines cool under the summer sun and helping the Merlot grape retain its backbone of acidity and not over ripen.
1855 Classification – defining an asset class
In 1855 the newly crowned Napoleon III decided that the greatest wines of Bordeaux should be showcased to the rest of the world. He requested that the Bordeaux brokers draw up a list of chateaux using quality as the key indicator. However, the brokers kept with tradition and ranked the estates by price alone. They used two parameters: the first being that wines came from the left-bank only (including Pessac-Leognon) and the second was the requirement that their annual production exceeded 2,000 cases.
The classification was decreed solely for the purpose of the great exhibition of Paris, but has been immutable ever since recording 58 red and 21 white wine producing properties of the Medoc ranked from Premier Cru to Cinquième cru.