The Blue Clay of Pomerol
By Martin Krajewski, proprietor, Clos Cantenac and Château Séraphine
The Pomerol appellation and its boundaries were only officially recognized in 1928 but the uniqueness of the divergent terroirs and soils here have remained unchanged for millions of years.
The highest point in Pomerol is known as the ‘Hill of Petrus’ but the terroir of the appellation is a complex blend of clay, gravel, sand, crasse de fer and iron oxide, although it is the clay laden soils that produce the richest, densest, most opulent and flamboyant wines of sensuous and rich character.
Clay is a product of degraded limestone, which explains why you often find limestone and clay located in the same terroir. This takes place because limestone is high in pH and calcium, which eventually breaks down due to time and erosion. Clay soils can also contain a high level of CEC, (Cation Exchange Capacity) which is important as it allows the soils to help bring more nutrients to the vines.
This unique clay-dominated terroir, along with the predominant plantings of Merlot vines, make it almost always the first major Bordeaux region to harvest, but there are several types of clay in the Pomerol soils and the most famous is the blue clay.
This blue, smectite clay is estimated to be close to 40 million years old and is incredibly dense making it almost impossible for the vines to penetrate. However, in wet vintages it acts as a sponge with an incredible ability to expand and retain water, although this must be balanced by effective drainage systems and gravels, which is exactly what naturally occurs at the best vineyards with blue clay.
As a result, the water molecules are able to penetrate the inter layer molecular spaces of the clay, so when the dry summer months arrive, the vines are still able to feed on the much needed moisture.
Therefore, it will come as no great surprise to hear just how absolutely delighted we were when Xavier Chone, our Conseil du Terroir (vineyard consultant) was actually able to confirm his already strong suspicion of the existence of the blue clay in our new vineyards at Château Séraphine. Xavier’s analysis involved excavating a series of three-metre deep trenches, which revealed this famous, but illusive sought-after commodity.
It was obviously a discovery of great joy and it brought enormous excitement, as it is an indicator that even in most severe drought years, we could still expect to harvest high quality fruit. This is a winemaker’s dream. When such crucial elements successfully combine, the result is one of great wines that are sensuous and hedonistic, offering complex perfumes of truffles, chocolate, flowers, dark cherries, plums and exotic spices, that not only entice and beguile, but also reward careful cellaring and patience.
Get these Pomerol wines through June 7, 2021
L’Innocence de Séraphine, AOC Pomerol, 2019, lot 2598