Dekuyper® Creme De Cassis. The brand bartenders trust. 30 Proof. Dekuyper Creme De Cassis brings you all-natural, bartender-quality flavor so you can mix classic cocktails or create your own signature drinks. Dekuyper is committed to providing you with cordials of the highest quality. We use the finest natural flavors, and our products do not contain high fructose corn syrup. Under license from De Kuyper Royal Distillers, Schiedam, The Netherlands. For additional recipes: www.dekuyperusa.com.