What is the author's tone in On Food and Cooking by Harold McGee?

The tone of the book is very light and instruction-like. The author speaks clearly, with extreme depth, but does not write in such a way as to make the text inaccessible. No knowledge of chemistry or history or sciences are necessary to understand the material presented. The topic is one of little controversy, so the tone is not combative. However, the author does lend his own opinions at times in terms of animal cruelty and the modernization of foods, and these areas are definitely opinionated, although not presented as accusatory or confrontational, but simply as factual. McGee presents his material as objective, factual and intellectual, which allows the book to move freely and smoothly between hundreds of different topics. With such a light tone, this vast book would not only be incomprehensible, but far too long to be effective. The light tone, peppered with interesting tidbits of history and modern tips for cooking, simply adds to the enjoyment of the book.