E & J Gallo Winery and Constellation Brands are two of America's largest wine companies.You probably know them by the many individual brands under their umbrellas.Gallo owns Barefoot, Dark Horse, and Apothic; Constellation has Mondavi, Charles Smith, and Kim Crawford.So what does it matter if Constellation sells over 30 of its brands to E & J Gallo—an $810 million move?.It's one of America's largest wine deals ever—taking two years of wrangling with regulators to receive approval.The sale has historical significance and could potentially set off alarms about consolidation in the wine industry. .But for consumers, in the short term, you probably won't notice many differences at all