Left Bank vs Right Bank: what is the difference?

Two rivers, not one

Left and right of 2 rivers, not one, and that is rarely the first thing anyone explains. The Garonne comes up from the south and the Dordogne comes in from the east. They meet at the Bec d’Ambès, about 25 kilometers downstream of the city, and run on as the Gironde, about 75 kilometers of estuary out to the Atlantic, as the map shows.

The Left Bank is the left side of the Garonne and the Gironde: the Médoc (opens in a new tab) to the north, Graves (opens in a new tab) and Sauternes (opens in a new tab) to the south. The Right Bank is the right side of the Dordogne and the Gironde: Saint-Émilion (opens in a new tab), Pomerol (opens in a new tab), Fronsac (opens in a new tab), Bourg and Blaye, the last 2 facing the Médoc across the water. Between the rivers lies Entre-deux-Mers (opens in a new tab), which is on neither bank and says so in its name.

Gravel for Cabernet, clay for Merlot

Gravel drains fast and warms quickly, which suits a late grape with thick skins; cold, wet clay does not, and Merlot, which flowers and ripens earlier, can still finish there. Why that decides the blend is the subject of the guide on gravel and clay. The river is only where the geology happens to change.

Where the rule fails

It fails on the Right Bank wherever there is gravel. Château Figeac (opens in a new tab) and Château Cheval Blanc (opens in a new tab) sit side by side at the western edge of Saint-Émilion, against the Pomerol line, and both are planted mostly to Cabernet. Figeac, on 3 outcrops of gravel about 7 meters deep, is Cabernet Franc (opens in a new tab), Cabernet Sauvignon, and Merlot in equal thirds. Cheval Blanc is 55% Cabernet Franc and 5% Cabernet Sauvignon. At Figeac, 2 vines in 3 are not Merlot.

Pomerol itself is a plateau of gravel over clay rich in iron oxide, and it is Merlot country all the same: La Fleur-Pétrus (opens in a new tab), on that plateau, is 91% Merlot. The gravel there sits on the clay, and the clay wins.

It fails on the Left Bank wherever the wine is not red, because the rule is only about red. The Graves also make white, and the Crus Classés de Graves (opens in a new tab), the classification of the Graves estates, are ranked for red, for white, or for both. Sauternes and Barsac (opens in a new tab), on the same bank, make sweet wine from white grapes, which the Médoc grows only for dry white.

And it fails, as a matter of arithmetic, at almost any estate you look at. A Médoc classified growth is Cabernet-led, but Merlot is in nearly all of them. Latour (opens in a new tab) is planted about 76% Cabernet Sauvignon and 22% Merlot, and Saint-Estèphe, on more clay, is 40% Merlot across the appellation. In a cold year it is Merlot that fills the middle of the wine.

Which bank is the wrong question

Use the rule as a first guess, and drop it the moment the soil contradicts it. The useful question is never which bank; it is what is under the vine.