Creating unique, flavorful, and visually captivating garnishes is a key element of advanced mixology. Guinness foam, with its rich and creamy texture, makes an exceptional topper for cocktails and Irish-inspired drinks. In this guide, we’ll show you how to use a siphon and the rapid infusion technique to make Guinness foam—a sophisticated garnish that adds depth and intrigue to your drinks. What is the Rapid Infusion Technique? The rapid infusion technique, widely used in cul