Often used in cocktails, what is gomme?

Gomme syrup (or gum syrup; gomme is French for "gum") is an ingredient commonly used in mixed drinks. It is also commonly used as a sweetener for iced coffee in Japan. Like bar syrups, it is a 2:1 sugar and water mixture, but has an added ingredient of gum arabic. Gomme syrup is made with the highest ratio of sugar to water possible, while the gum arabic prevents the sugar from crystallizing and adds a smooth texture.

The thicker, sweeter syrup helps to smooth the harsh flavor of alcohol in cocktails. While rarely available in bars today, many original recipes for classic cocktails, dating to before Prohibition, call for the thicker syrup. Gomme syrup is available in several commercially prepared products, available at better restaurant or bar supply stores as well as online.