The winery is located in the municipality Saint-Estèphe or the same area in Médoc (Bordeaux). From the famous Château Lafite-Rothschild it's only separated by a stream. Part of the vineyards was dissolved in 1789 and with that the Château Cos Labory founded. The founding year of the Château Cos d'Estournel is 1811, when the horse and wine dealer Louis-Gaspard d'Estournel (1753-1844) acquired the first vineyards. He recognized the quality of the extremely barren pebble floors (Cos) early on. The name part "Cos" (Caux) is derived from "Colline de cailloux" (gravelly hill). Louis-Gaspard d'Estournel exported his wine to India and Arab countries. From there he imported noble horses that were bred in the pastures around the vineyards. He built a huge wine cellar in partly Asian style, including the pagoda-like roofs and the famous door from the harem area of the Sultan of Zanzibar.
By chance, Estournel recognized the value of shipping wine in wooden barrels when unsold wine was brought back from India. He compared it to the same wine that stayed at home and noticed a significant improvement in quality. When sold, they achieved far better prices. Therefore, after some time, all wines were sent on a boat trip before being sold and marked with an "R" (Retour des Indes = back from India). You could therefore be one of the "inventors" or at least the first users of the Aged expansion indicate (whether these barrels already toasted were, however, is not known). In the medium term, however, this complex process led to a financial fiasco. The estate was therefore sold to the London banker Martyns in 1852. In the Bordeaux Classification in 1855 the château received second place under the name "Cos Destournel" (Deuxième Cru Classé).
After an eventful history, the estate came into the possession of Yves, Jean-Marie and Bruno in 1970 Prats, The latter acted as managing director until 1998. During this time, the term "Super-Seconds" was born. This means that the wine would earn the "Premier Cru Classé" due to its high quality. This was thanks to Bruno Prats, who worked with immense perfection and with the most modern methods. In 1998 the property was sold to the Taillan Group and finally sold to Michel Reybier in 2001. Today it is run by Prat's son Jean-Guillaume.
The total property covers 100 hectares, of which 67 hectares are planted with vines. These are Cabernet Sauvignon (60%), Merlot (38%) and Cabernet Franc (2%). The extremely long-lived red wine matures in 18 to 24 months in 70% to (in particularly good years) 100% new barriques, The second wine is called "Les Pagodes de Cos". The branded wine "Maître d'Estournel" produced under the appellation "Bordeaux" was created in 1971 by Bruno Prats. The name is given to the legendary founder Louis Gaspard d'Estournel. The red wine is made from the varieties Cabernet Sauvignon, Merlot and Cabernet Franc, the white wine from Sauvignon Blanc, with the grapes coming from all over the region. These are significantly cheaper wines.