Malbec was once a major component in the great wines of Bordeaux (where it is known as Cot), but more recently it has also been relegated to a minor role there. It has been steadily replaced by Merlot and the other two Cabernets in most parts of Bordeaux. In the Medoc, it is mainly used to add colour and tannin to the encepagement. In fact, if Petit Verdot was easier to grow, Malbec would likely have even less acreage under vine than it does today. It is the key grape only in the small appellation of Cahors (south west France), where it is known as Auxerrois. In Cahors, the wines are dark, rustic, full and soft, with earthy tobacco aromas alluding to Bordeaux.
Argentina is now regarded as the new home of Malbec. In Mendoza, under the shadow of the Andes Mountains, the grape enjoys its vacation from the more moderate climate of the Medoc. Here, there are hot summer temperatures and the grape is left hanging long into the growing season to ripen and soften its rough tannins. The Malbec grape is a thin skinned grape (in warm climates, thick skinned at high altitudes) and needs more sun and heat than either Cabernet Sauvignon or Merlot to mature. It ripens mid to late harvest and it can bring very deep colour, robust tannin, and a particular plum-like flavour component to add complexity to red blends.
The best of Argentine Malbecs' are deep inky reds with juicy dark fruit and soft tannins, making a very approachable, early drinking style of wine. Malbec is also found in Chile, Australia, South Africa and New Zealand (Waiheke Island and Hawke's Bay are producing some interesting examples), and it is used as a blending grape in Bordeaux-style blends - (one of the famous five red grapes).