Rob Cooper, founder of Cooper Spirits Co. and creator of the wildly popular St. Germain elderflower liqueur, died April 25 in Santa Barbara, CA, according to reports. He was 39. The cause of death was not immediately known.

Cooper, whose family owned Philadelphia liqueur firm Charles Jacquin et Cie, launched St. Germain in 2007. The product’s unique flavor and beautiful Art Deco-bottle packaging helped make it an instant hit with bartenders. The launch’s timing also dovetailed nicely with the start of the craft cocktail movement.

After selling St. Germain—one of Cheers’ top 20 product launches of the past 25 years—to Bacardi about five years ago, Cooper went on to create several new spirits. These include the violet-berry liqueur Crème Yvette, Hochstadter’s Slow & Low and Lock Stock & Barrel rye whiskey. Read more in this New York Times article.