Opus One Winery is a winery in Oakville, California, United States. The wine was called Napamedoc until 1982 when it was named Opus One. The winery was founded as a joint venture between Baron Philippe de Rothschild of Château Mouton Rothschild and Robert Mondavi to create a single Bordeaux style blend based upon Napa Valley Cabernet Sauvignon. It is located across State Route 29 from the Robert Mondavi Winery.
The genesis of Opus One wine can be traced to 1970 at the Mauna Kea Beach Hotel on the Big Island of Hawaii where Robert Mondavi and Baron Philippe de Rothschild met for the very first time and began their collaboration to merge old world and new world wine styles into one grand opus. The joint venture between Mondavi and Baron Rothschild was announced in 1980, In 1980, Mondavi sold 35 acres from his To Kalon Vineyard in the Oakville AVA to the joint venture that would serve as the backbone for the blend. The first vintage from this block was released in 1985 and soon the estate built the large limestone winery in Oakville that has become an icon of the Napa Valley.
In the 1990s, Opus One became the California cult wine to be widely sold in Asia and Europe. Following Constellation Brands' 2004 takeover of Robert Mondavi winery, the estate of Baron Rothschild negotiated with Constellation Brands control of marketing, vineyard management, and administration of the winery.
To date, it still ranks among the most expensive red wines produced in the Napa Valley, with the 2014 vintage retailing for $325 per bottle.