Like so many other cocktail enthusiasts, my personal mania for carbonated cocktails started when I first read Dave Arnold's Liquid Intelligence. It's where I first learned that carbonation is an actual flavor, like salty or sour, and should be treated like an ingredient, not an afterthought. It's also where I learned just how difficult carbonation is to achieve and sustain -- which is why so many G&Ts, for example, are practically flat by the time we consume them.