Château Cos d'Estournel, located in Saint-Estèphe, has a rich history dating back to 1811 when Louis Gaspard Lacoste of Maniban Marquis d'Estournel decided to produce wine from vineyards near the village of Cos. In 1855, Château Cos d'Estournel was classified as a second growth. Since then, the estate has had five owners, with Michel Reybier acquiring it in 2000 and implementing significant changes, including the construction of a new barrel cellar and a gravity winemaking cellar, which was a groundbreaking innovation in the region.

The vineyard of Château Cos d'Estournel spans 91 hectares and benefits from diverse terroirs. The southern slopes with meager peaks provide ideal conditions for Cabernet Sauvignon, which represents 60% of the vineyard. On the eastern slopes and coasts, where the limestone basement of Saint-Estèphe is exposed, Merlot thrives, accounting for the remaining 40% of the vineyard. Only vineyards over twenty years old bear the name of Château Cos d'Estournel. The vine density ranges from 8,000 to 10,000 feet per hectare, and the farming methods are primarily manual, with careful sorting of the grapes during the harvest.

The vinification process at Château Cos d'Estournel is tailored to the character of each harvest, with a focus on expressing the terroir. The new cellar enables precise grape sorting and pure gravity pumping, using lift tanks to avoid introducing air and destabilizing the marc. This pumpless approach allows for the purest expression of the fruit grown in the gravelly, rock, and stone terroir of Cos d'Estournel. The wine ages in new oak barrels for approximately 18 months, adding subtle woody nuances to the aromas and flavors.

The estate's vineyard is a mosaic of 61 plots with different soil types, including gravel, clay, sand, and limestone. This unique combination contributes to the complexity and distinctive characteristics of the wines. The vineyard's proximity to the Atlantic Ocean and its cool climate, along with the beneficial winds that dry excess humidity and purify the air, allow for gentle ripening of the grapes, resulting in freshness and complexity.

In addition to the renowned red wines, Château Cos d'Estournel produces a white wine, Cos d'Estournel Blanc, from Sauvignon Blanc and Semillon grapes grown in the Jau-Dignac and Loirac regions. The white wine undergoes barrel fermentation and extended aging in French oak barrels.

Château Cos d'Estournel's commitment to quality extends to its second wine, Les Pagodes de Cos, which has gained recognition as one of the finest second wines in Bordeaux. It is crafted from selected parcels, including young vines and declassified wine intended for the Grand Vin. The estate also produces Goulee by Cos d'Estournel, a wine from their vineyard in the Medoc, and has acquired vineyards in Tokaji and Provence.

With its rich history, commitment to quality, and innovative winemaking techniques, Château Cos d'Estournel stands as one of the leading producers in Bordeaux. The wines are known for their richness, concentration, elegance, and age-worthiness, and they continue to improve with each vintage.