Chateau Picard was an estate red wine produced at the Picard vineyards in La Barre, France. The head vigneron or winegrower during the mid-24th century was Robert Picard. This chateau's wine was trademarked and bottled at a castle.
Jean-Luc Picard reserved a few bottles of this wine on the USS Enterprise-D and USS Enterprise-E for special occasions. Picard poured two glasses of this wine and offered a toast to Chancellor Durken after initiating First Contact with the Malcorians. (TNG: "First Contact")
Background information Edit
By coincidence or not, Chateau Picard is a real wine label, although it is made in Saint Estèphe. Originally, this chateau's name was Chateau La Barre, as seen on a wine bottle label. Some of the information in the article is from this bottle. 
The bottle of Chateau Picard is seen in the DS9 Season 1 DVD special feature "Secrets of Quark's Bar" presented by Penny Juday, although the prop was not used in Star Trek: Deep Space Nine but in Star Trek: Nemesis.
Two Chateau Picard wine bottles were sold as Lot #27 in the 40 Years of Star Trek: The Collection auction. The winner paid US$6,600, even though the pre-sale estimate was 500 to 700 dollars. After the sale, the auctioneer remarked "That's probably a record for empty wine bottles."
The 2012 Star Trek: Starfleet Academy novel "The Assassination Game", set in the alternate reality, mentions a bottle of Chateau Picard being served by James T. Kirk to Leonard McCoy and his date Nadja Luther (β). Upon reading the label, Kirk remarks, "Chateau Picard. Never heard of it."