Sasha Petraske, who helped restore lost luster to the venerable cocktail as the founder of the New York cocktail bar Milk & Honey and other polished drinking spots around the world, was found dead on Friday morning at his home in Hudson, N.Y. He was 42.

His wife, Georgette Moger, said he had died overnight. The cause had not been determined, she said.

Mr. Petraske’s role in the modern cocktail revival is difficult to overstate. The opening of Milk & Honey in 1999, in a narrow space on a dark, little populated block of the Lower East Side, has been called instrumental in the revival of cocktail culture across United States and beyond.

Though unmarked and unadvertised, Milk & Honey became a phenomenon, known for its unapologetic dedication to expertly crafted, pre-Prohibition era cocktails, not to mention its eccentric reservation system and exacting rules of decorum. In a Manhattan bar world then ruled by glitz and noise, sloppy drinks and sloppy behavior, it served as both a rebuke and a utopian alternative.

Mr. Petraske went on to open similarly urbane and serious-minded bars with a number of partners, many of them former Milk & Honey bartenders. These included Little Branch in Greenwich Village; Dutch Kills in Long Island City, Queens; Middle Branch in Midtown Manhattan; the Varnish in Los Angeles; and the Everleigh in Melbourne, Australia. Mr. Petraske also opened a roomier version of Milk & Honey in London with Jonathan Downey, a British entrepreneur.