The contemporary cocktail book is a beautiful thing. The renaissance of cocktail culture has been brought about by a cadre of talented and innovative mixologists who are obsessive about the art and craft of making cocktails, and who are able to write intelligently. Speakeasy by Jason Kosmas and Dushan Zaric of Employees Only in Greenwich Village, Dale Degroff’s The Craft of the Cocktail, and The Craft Cocktail Party by Julie Reiner are all excellent books, loaded with useful advice for the home cocktail afficionado; and they express a passion for fresh ingredients applied to variations on classic cocktails.
Liquid Intelligence is different. Dave Arnold is as passionate as the others about cocktails made from fresh ingredients, but takes a systematic and scientific approach. He measures everything he can, debunks misconceptions through the power of data, and gains understanding of cocktail construction from models based on his data.
After the usual preliminaries about bar tools he talks about ice. For several pages he talks about ice: its chemical and physical properties; how to make clear ice; why clear ice is a good thing; how dilution relates to chilling (“The Fundamental Law of the Classic Cocktail”); and how ice relates to the relative effects of acidity and sweetness. The Fundamental Law is : there is no chilling without dilution, and there is no dilution without chilling. And the law is essentially independent of the size of the ice: everything from a large rock to crushed ice causes chilling in proportion to dilution - crushed ice is just a whole lot faster. The Fundamental Law invalidates a misconception that I had: namely, that it is better to have super cold ice when shaking a drink. But in fact, you want ice that is just at freezing, because most of the chilling occurs by melt water, not by the ice itself. Good to know.
He conducted a series of experiments on the rate of chilling by shaking and by stirring across a range of alcohol by volume (ABV). Then, using Excel, he created a quadratic model that can predict chilling (and therefore dilution) based solely on the ABV of the cocktail. Impressive, though I suspect the model is not very robust: the coefficient of the high order term is negative in the case of stirred cocktails - an indication that a quadratic model is not correct for that case. But, no matter, the data is probably valid of the range of ABV found in drinkable cocktails.
He includes a database of characteristics of about 50 spirits and mixers, listing their ABV, acidity and sweetness. Using this database he is able to construct drinkable recipes based solely on a mathematical model that he formulated that relates ABV, sweetness, and acidity: by matching the profile of classic cocktails he is able to determine the correct proportions of spirits and mixers that have, perhaps, never been combined before.
So this is a book that takes a fresh approach, and is a worthy addition to anyone’s cocktail library.