Opus One is one of the world's most famous wines, and is a partnership of two of the most respected figures from Bordeaux and Napa Valley, Baron Philippe de Rothschild of Château Mouton Rothschild and Robert Mondavi. It was the first premium California wine sold in Europe. It continues to be one of the most expensive Cabernet Sauvignon-dominant wines produced in Napa Valley.
The collaboration was conceived in the 1970s and then first realised in 1979, when the first vintage of Opus One was created. It was released to the public in 1984, but had already attracted attention, as a single case of the wine had sold for $24,000 at the first Napa Valley Wine Auction in 1981. Opus One's brand grew considerably in the 1990s, particularly in markets outside of the United States, and in 2005, when Robert Mondavi Winery was acquired by Constellation Brands, Opus One also became part-owned by the multi-national company.
Opus One is a single wine, a Bordeaux Blend sourced from the estate vineyards in Oakville, which include blocks of the famous To Kalon vineyard. The grapes are hand-harvested, and gravity flow is used to get the fruit from the destemmer into stainless steel tanks for fermentation. The wine is then aged in new French oak for a year and a half, during which time blending takes place. After an additional year and a half in bottle, Opus One is released to the market. Although it is primarily Cabernet Sauvignon, Opus One makes use of Merlot, Cabernet Franc, Petit Verdot and Malbec in smaller percentages.