Bordeaux has established a "recipe" for claret that involves mixing three main and several lesser varieties. The proportions of the mixture are the decision of the winemaker, however: there is no insistence on one variety, as in Burgundy.
Cabernet Sauvignon Dominant in the Medoc, especially in the classed growths, where it can be 80% of the blend. In the top AOCs (Pauillac, St-Julien, Margaux) the variety finds the well-drained gravel soils it thrives best on. Also important in red Graves. Less dominant in St-Emilion, where it appears in small proportions, or not at all, as the heavier limestone-based soils do not suit it. Cabernet Sauvignon-based wines are long-lived, tannic when young, and capable of developing great finesse. Carmenere, a variety listed in the regulations, is another name for Cabernet Sauvignon.
Cabernet Franc Plays the dominant role in St-Emilion, where it partners Merlot in most wines, but is a minority grape in the Medoc, Graves and most other red-wine districts. It gives less "structure" than Cabernet Sauvignon, but adds fruit and fine aromas.
Merlot The key to Pomerol, the most important grape in much St-Emilion, and a part of the blend of most Medoc and Graves wines. Merlot brings colour, fruit and suppleness to the blend. It thrives on heavier (and thus colder) soils, where the Cabernets are unhappy.
Malbec Once quite widely grown in the Medoc, where its early ripening and fruity, deep-coloured wine made it a useful wine to blend with the Cabernets. It has declined due to disease problems, and is now a minority variety.
Petit Verdot A later-ripening variety making tannic, dark wine. It is useful as a small proportion of a blend, as its wine ages well. Less common than formerly, it is mainly grown in the Medoc.
WHITE WINES The balance between Sauvignon Blanc and Semillon, the two main quality white wine grapes, alters according to the fashion of the decade and the style of wine required. Sauvignon, with lots of fresh, grassy aromas and a dry finish, became popular in the 1980s. Most white Graves and Sauternes use both, in varying proportions.
Semillon The most widely planted white variety, which is responsible for much ordinary white bordeaux and a small, but important, amount of great sweet wine. It can gain from the otherwise dreaded botrytis rot which concentrates its sweetness: For dry wines, and some sweet ones, it is blended with Sauvignon Blanc.
Sauvignon Blanc Important in white Graves, and in Sauternes as a minor partner with Semillon, and in recent years planted widely for dry wines in the Entre-Deux-Mers and outlying districts.
Muscadelle A minor component of dry and sweet white wines, adding perfume and a pungent flavour.