Brew Chem 101: The Basics of Homebrewing Chemistry

Rating:
Summary: A simple and short review of beer brewing
Review: As the name implies, Brew Chem 101 was written for the beginning to intermediate brewer who wants a relatively short, non-technical and readable explanation of some of the basic chemical and biochemical reactions essential to making beer. Many introductory brewing books leave these explanations out for sake of space and clarity, potentially leading to common beginning brewing mistakes and off-flavors. By reading Brew Chem 101, you'll have a far better understanding of the brewing process and understand why you do what you do and when. The best part is your beer and the fun of brewing will improve dramatically. Importantly, the book is not designed for established brewers who should instead consult some of Dr. George Fix's works (referenced in Brew Chem 101), although it may serve as a useful library reference for those readers as well.

Rating:
Summary: Informative, concise book on how to make & enjoy better beer
Review: Brew Chem 101 clearly informs the reader what happens when grain, water, hops, and yeast come together to produce beer. Janson's non-technical book is the shortest book I've read on brewing, but the most informative and the easiest to follow. You don't need a chemistry or math background to comprehend this easy to read book. Its a great book for the beginning and advanced brewer alike or for anyone interested in beer. Janson starts off with a quick overview of the Basic Chemistry of Beer (chapter 1). He follows with Biochemistry of Beer (2), Yeast and Fermentation (3), Mashing and Sparrging (4), and Understanding and Avoiding Off Flavors (5). The author, a certified beer judge, then leaves the subject of beer production to address Evaluating Beer in his last chapter. In the middle of this chapter on prepouring, pouring, smelling, looking, and tasting, Janson puts things in perspective by stating: "Just sit back and taste it for pure, unadulterated enjoyment." Janson complets his book with a usefull glossary and annotated bibliography ("Further Reading")

Rating:
Summary: Misleading title
Review: Brew Chem 101 is an informative book that is targeted for the home-brewer who is just moving into mash-extract or all-grain brewing. The author keeps the explanations simple and gives definitions of the terms used. It's a good introduction to the chemistry of brewing for people who don't have a lot of chemistry background. I had thought it would get a little more in depth in explanation of chemical reactions, but after realizing who this is written for I would say it is a good start for someone wanting to learn the very basics. Advanced All-Grain brewers need not read this book though since it spends a lot of time explaining the proceedures and why they are done.

Rating:
Summary: This book is targeted towards advanced-beginner home brewers
Review: Brew Chem 101 is an informative book that is targeted for the home-brewer who is just moving into mash-extract or all-grain brewing. The author keeps the explanations simple and gives definitions of the terms used. It's a good introduction to the chemistry of brewing for people who don't have a lot of chemistry background. I had thought it would get a little more in depth in explanation of chemical reactions, but after realizing who this is written for I would say it is a good start for someone wanting to learn the very basics. Advanced All-Grain brewers need not read this book though since it spends a lot of time explaining the proceedures and why they are done.

Rating:
Summary: Misleading title
Review: I was very appointed when I finished this book. The book is not meant for advanced brewers and did not explain any chemical reactions of the brewing process at all. The author even makes a few errors while explaining the proces of brewing. The chapter of offflavours is slightly interesting. My opinion: if you want to buy a goof book on advanced brewing techniques buy the book An Analysis of Brwing Techniques from Fix

Rating:
Summary: Excellent introduction
Review: This is a clear, concise and not too nerdy intro to brewing chemistry. For advanced home-brewers or chem buffs it might be too basic, but for us non-nerdy types this book will be very helpful. The book is only about 100 pages, so it isn't a major undertaking to get through. The author deliberately avoids getting too technical and keeps things simple. So rather than discussing exhaustively the many chemical reactions in the brewing process he tends to highlight the most important molecules and chemicals, discussing their properties and what qualities they contribute to the final beer (such as fruity, spicy, dry, bitter, pleasant, unpleasant, etc.) This book would make a good stepping stone to George Fix's book on brewing chemistry, which is more techical and requires some knowledge of biochemistry and some math too (not too surprising, since George was a Harvard mathematician). If you've read books on home-brewing and want more information, this book will be very helpful.

Although brewing chemistry is quite complex if one considers all the details, the basic idea is quite simple. Yeast ferment a sugar-rich combination of malted barley (or other grains, such as rye or wheat) and hops to produce alcohol and a variety of other metabolites that give the different flavors and qualities to beer. For example, I learned that one difference between lager and ale yeasts, besides the well-known distinction that ale yeasts are warm temperature, bottom-fermenting and lager yeasts are cold temperature, top-fermenting, is their ability to digest the sugar raffinose. Unlike sucrose or glucose, which are disaccharides and monosaccharides, respectively, raffinose is a heavier trisaccharide and ale yeasts are unable to metabolize it. Thus, heavier sugars, such as amylose, amylopectin, and so on, get into the final brew, which is why ales are typically heavier, fruitier, and sweeter than the cleaner and dryer-tasting lagers. The yeast primarily digests glucose, fructose, and sucrose, and maltose. Melibiose, a disaccharide like sucrose or maltose, is also present but can't be used. This is because the bond between the two glucose molecules is the same as raffinose.

The other important ingredient is hops. Hops are just the leaves of the hop plant, and the important thing is that the leaves contain glands that house essential oils and acids that provide bittering and flavoring to the finished brew. Although these glands contain 250 essential oils, the most important ones are the alpha acids such as humulone, cohumulone, and adhumulone, which are derived from the soft resins in the glands. The beta acids derived from the hard resins are less desirable. It is the isomerization of the desirable alpha acids, the changing of the molecule to a slightly different structural configuration with the same chemical constitution, that produces the pleasant bitterness in beer. The beta acids produce a less pleasant and desirable bitter quality.

Terpene molecules such as myrcene and humulene are also important. The oxygenation of humulene gives an elegant and refined flavor and aroma to beer. The same thing happens with myrcene, which produces a floral and herbal character from the production of two molecules, geraniol and linolool, and two other related molecules, geranyl acetate and geranyl isobutrate. However, this is also accompanied by a bitter quality that can be unpleasant if these myrcene by-products are present in too great a quantity, which is usually only a problem with certain species of hops, such as the Cascade strain, which contain high percentages of myrcene. But the widely used Cascade strain is prized for the floral and spicey ales they can produce.

There is also a discussion of ions and their contribution to flavor. For example, the English Burton ales are famous and use water from Burton on Trent which is high in calcium, sulfates, magnesium, sodium, and chloride. Janson notes that the presence of these molecules (and in the hands of competent brew-masters) results in a very complex and delicious brew, which is why one must pay attention to the quality of the water for certain styles of beer.

Well, I've gotten more nerdy in this review myself than I intended. But Janson's book will provide you with much more information if you're interested. Overall, a very readable and informative introduction to the area of brewing chemistry. After reading this, if you're game, pick up Dr. George Fix's Principles of Brewing Science, which is more technical, but which bridges the gap between the even more technical journals and big professional manuals of brewing chemistry. If you can get through that you're definitely eligible for your brewing chemistry nerd badge.

Rating:
Summary: Disappointing.
Review: While you get the impression that the author knows his stuff, he doesn't write much of it down. The information provided is incomplete and not well supported, either with explanations or references. No topic is addressed in sufficient depth or detail as to provide a basis for good brewing decisions.

I would recommend that anyone interested in a good introduction to the chemistry and biology of brewing instead acquire either one or both of George Fix's books, "Principles of Brewing Science" and "Analysis of Brewing Techniques".