What are the predominant red grapes used in the making of Bordeaux wine?

Bordeaux wine is produced in the Bordeaux region of southwest France, around the city of Bordeaux, on the Garonne River. To the north of the city the Dordogne River joins the Garonne forming the broad estuary called the Gironde; the Gironde department, with a total vineyard area of over 120,000 hectares, is the largest wine growing area in France.

Red Bordeaux is generally made from a blend of grape varieties. Permitted grapes are Cabernet Sauvignon, Cabernet Franc, Merlot, Petit Verdot, Malbec and rarely Carménère. Today Carménère is rarely used, with Château Clerc Milon, a fifth growth Bordeaux, being one of the few to still retain Carménère vines. As of July 2019, Bordeaux wineries authorized the use of four new red grapes to combat temperature increases in Bordeaux. These newly approved grapes are Marselan, Touriga Nacional, Castets, and Arinarnoa.

As a broad generalisation, Cabernet Sauvignon (Bordeaux's second-most planted grape variety) dominates the blend in red wines produced in the Médoc and the rest of the left bank of the Gironde estuary. Typical top-quality Châteaux blends are 70% Cabernet Sauvignon, 15% Cabernet Franc and 15% Merlot. This is typically referred to as the "Bordeaux blend". Merlot tends to predominate in Saint-Émilion, Pomerol and the other right bank appellations. These Right Bank blends from top -quality Châteaux are typically 70% Merlot, 15% Cabernet Franc and 15% Cabernet Sauvignon.