Although Janson claims this course in chemistry for the nonchemist is for “the homebrewer whether beginner or expert,” it likely will be of most help to the intermediate or advanced home-brewer eager to fine-tune and standardize output. Janson tries to keep the hard science to a minimum and explains terms and processes fully and clearly. Still, he charts a lot of molecular structures, but his explanations are so comprehensive and his perception of common home-brewing problems so canny that the technical material won’t drive readers away. The chapter on avoiding “off” flavors alone is worth the price of the book, and the chapter on evaluating beer and the insightful glossary just make it better. So if you are concerned about flocculation and avoiding that “baby diaper” or “skunky” taste and aroma, make this required reading.