Which varietal is often blended with Cabernet Sauvignon in Bordeaux?

In Bordeaux, Cabernet Sauvignon is commonly blended with Merlot to create some of the region's most celebrated wines. This blend takes advantage of the strengths of each varietal; Cabernet Sauvignon provides structure, tannin, and aging potential, while Merlot contributes softness, fruitiness, and earlier drinkability. The combination results in a well-balanced wine with complexity and depth.

Merlot thrives in the clay and limestone soils of Bordeaux, often blending seamlessly with Cabernet Sauvignon to enhance the bouquet and flavor profile, making it a key player in Bordeaux's red wine production. This partnership is reflective of the traditional blending practices in the region, which prioritize building complexity and harmony in the final wine.

The other varietals listed—Malbec, Syrah, and Tempranillo—are not typically associated with Bordeaux blends. Malbec does have a presence in some Bordeaux wines but is not as predominant as Merlot. Syrah is more commonly found in the Rhône Valley, and Tempranillo is primarily the star grape of Spain, particularly in regions like Rioja. Thus, the unique role of Merlot in the Bordeaux blend solidifies its status as the correct answer.