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D. A. Thomas
- Publié sur Amazon.com
Water: A Comprehensive Guide for Brewers (Brewing Elements)
In 1884, J.A. Nettleton published Every Brewer His Own Analyst, A plain and brief Summary of Reliable Chemical and other Practical Tests Which are applicable to All Brewing Waters and Materials, To Worts and To Beer, And which can be performed readily by every Brewer, (Ford, Shapland & Co., London), devoting thirty-two of the sixty page booklet to the science of brewing waters as it was known. Since then, brewing chemists have endeavored to further understand and explain all aspects of beer's principal ingredient.
The newest contribution to brewing water wisdom is Water, a comprehensive guide for brewers by two authors well known in the US Craft Brewing world, John Palmer and Colin Kaminski. Palmer previously penned How to Brew and co-authored Brewing Classic Styles for Brewers Publications. Kaminski designed more than 180 home-brewing gadgets at Beer, Beer and More Beer homebrew supply shop (Concord, California).
The book begins with chapters on brewing water overview, sources of brewing water and how to read a water report. The authors encourage brewers to "...contact the [municipal] water department at least monthly to get current information"... and..."the water department is usually happy to supply information on the Secondary Standards for brewers." Primary standards are those that the US Environmental Protection Agency (EPA) Clean Water Act for drinking water has set maximum contaminant levels, whilst Secondary Standards are those that are unregulated or merely aesthetic in nature.
Chapters 4 & 5 explain the fundamental importance and relationships between malt color, malt acidity, malt buffering capacity, liquor/grist ratios, malt mill gap settings, mash pH and residual alkalinity. The authors introduce and define the concept of "Z Residual Alkalinity" which takes into account the brewery's target mash pH (usually pH 5.2-5.6) rather than the standard pH 4.3.
Revealing a humorous side, the authors introduce Chapter 6, Controlling Alakalinity, with a tongue-in-cheek "Declaration of Non-Adherence", mimicking the US Declaration of Independence. Jocularity aside, methods of reducing brewing water alkalinity including acidification, boiling, lime softening or dilution with reverse osmosis (RO) or de-ionized (DI) water, as well as several methods to use when alkalinity needs to be increased with sodium bicarbonate, chalk, sodium or potassium hydroxide or slaked lime are discussed in detail. Chapter 7 then applies these chemistries to some six dozen different beer styles. Real brewery examples of source water treatment, brewing, bottling and boiler water requirements, and wastewater treatment scenarios are outlined in the final chapters of the book.
Since water analysis may be reported in a wide range of units, the authors have done much of the chemical unit calculation work for brewers by providing a nifty table of factors to convert between ppm and milliequivalents/litre for the important calcium, magnesium and carbonate water hardness ions.
Though at least one terrestrial and several shipboard breweries brew with distilled seawater, it is not mentioned in the book. As most futurists predict that fresh drinking water will only become more constrained by the earth's population, perhaps future works will expound on this option.
As recommended by the authors, brewers should have a basic knowledge of high school chemistry to read this book and grasp much of the science discussed within. A handy glossary and chemistry primer is also provided in the appendix to remind the reader of forgotten chemical concepts. Acidification of sparge water; ion, salt and acid calculations; and water charge balance and carbonate species distribution are also provided in appendices for those that can't get enough of brewing water chemistry. For the rest of us, this book fits the bill nicely.