This is a fairly technical discussion of the subject of brewing chemistry. It's probably more than your typical home-brewer will want to get into, but if you've got some biochem background, or have read Dr. Lee Janson's Brew Chem 101 book and are looking to read on from there, (or you're a very masochistic home-brewer :-)) this would be the next step to take. It does require a greater knowledge of biochemistry and some math (not too surprising, since Dr. Fix had a Ph.D. in math from Harvard). I note the problems with the citations another reviewer here mentioned, who said Dr. Fix refers to his own work and his other book too often, but I didn't mind that too much. Dr. Fix was certainly a competent professional in both math and brewing chemistry, and he did much important work on his own. The important thing is that this book helps to bridge the gap between the professional manuals of industrial microbiology and brewing chemistry and the professional literature. After completing this book, if you want more information, you'll have to go there, such as:
1. Beer and Wine Production: Analysis, Characterization, and Technological Advances (ACS Symposium, No. 536)
2. Biotechnology of Malting and Brewing by James S. Hough
3. Malting and Brewing Science: Hopped Wort and Beer (Volume 2) by D. E. Briggs, et al
4. Brewing Microbiology by Iain Campbell
5. Methods of Analysis of the American Society of Brewing Chemists, by the American Society Of Brewing Chemists
6. Malting and Brewing Science : Volume 1 (#Y0343)
by Dennis Edward Briggs, James S. Hough
7. Brewing Yeast and Fermentation by Chris Boulton, David Quain
Except for the Brewing Microbiology book by Campbell, all of the above are big, expensive professional volumes, but they represent some of the best technical titles out there.
The book also has a nice introduction summarizing some of the important developments of the last 20 years that have made great improvements in beer, such as the use of modern double pre-evacuation bottle filters to cut down on cold-side oxygenation, the awareness of the staling effects of unsaturated long-chain aldehydes, the realization that hot-side aeration could contribute to this, and the importance of malting and non-enzymatic browning also in this process. These were all important developments that led to the modern low-oxygen brewhouse.
So overall, a very fine discussion of all these issues, and I'd actually give the book 4.5 stars if I could.