Second Edition. Senior Lecturer in Biochemistry School of Biosciences The University of Birmingham Birmingham, United Kingdom

Transcription

1 Brewing Second Edition Michael J. Lewis, PhD, FIBrew Professor Emeritus of Brewing Science University of California, Davis Academic Director of Brewing Programs University Extension Davis, California Tom W. Young, PhD, FIBrew, ILTM Senior Lecturer in Biochemistry School of Biosciences The University of Birmingham Birmingham, United Kingdom Springer Science+Business Media, LLC

2 Library of Congress Cataloging-in-Publication Data Lewis, Michael, Brewing / Michael J. Lewis, Tom W. Young. 2nd ed. p. cm. Includes bibliographical references and index. ISBN ISBN (ebook) DOI / Brewing. I. Young, Tom W. II. Title. TP570.L '.3 dc21 Copyright 2001 by Aspen Publishers, Inc. Springer Science+Business Media New York 2001 Originally published by Kluwer Academic/Plenum Publishers in 2001 http: // All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the publisher, with the exception of any material supplied for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Library of Congress Catalog Card Number: TP570.L ISBN

3 Contents Preface Part I. Components Overview of the brewing process Basic chemistry for brewing science Heat transfer and refrigeration Water for brewing Microbiology and microbial contaminants of brewing Beer quality and flavor Analytical methods and statistici\l pro..:..::;:; Lontwl Cleaning and sanitation Part II. Processes Barley Malting technology: malt, specialized malts, and non-malt adjuncts Malting biochemistry Mashing technology Mashing biochemistry Hops technology Hops chemistry and wort boiling Brewer's yeast Fermentation: overview, process, and technology Fermentation biochemistry Finishing processes Beer packaging and dispense Additional Reading Index iii

4 Preface The second edition of this little book on brewing arises because many readers told us they found the first edition useful. We were pleased and encouraged and even flattered by that, as any authors would be. This second edition gives us the chance to correct some things that needed correcting and to add two chapters that should have been in the first edition but somehow got overlooked-a chapter devoted to water and another to analytical methods and statistical process control (Chapters 4 and 7). We hope we have heeded the advice not to turn a useful little book into a big clumsy one, but nevertheless we have also added some material on engineering subjects. One of these additions is a stand-alone chapter on heat transfer and refrigeration (Chapter 3) and we have added sections to Chapters 17 (fluids), Chapter 19 (carbonation) and a little to Chapter 20 (packaging). The engineering material deliberately falls far short of a standard course on brewery engineering (which is a different book from this one and one that we will not write!). The objective here is to demystify the subject, as far as possible, by showing how engineers do what they do, and to expose our nonengineer readers to some principles of engineering that (whether they know it or not) they observe and work with every day in the brewery. We hope that through an understanding, or at least an appreciation, of these principles, solving everyday problems may prove easier and elementary mistakes might be avoided. We have some colleagues to thank. We are most grateful to professor emeritus of food engineering R. Larry Merson whose impeccable attention to the new engineering material was immensely helpful; to the Anheuser-Busch endowed professor of brewing science Charles W. Bamforth who made wise and perceptive comments on the malting and brewing chapters and to Ms. Candace Wallin for her Trojan work on the section on brewing calculations. These are all colleagues at the University of California Davis, Department of Food Science and Technology. We are delighted, incidentally, to say that the research and teaching program in malting and brewing science continues there under the new and tireless and charismatic leadership of Charlie Bamforth. Tom Young remains active in research and teaching at the University of Birmingham, UK, as Senior Lecturer of Biochemistry. Since the first edition was written one of us (MJL) has retired from the University of California v

5 vi PREFACE Davis and now enjoys the honorific professor emeritus of brewing science. However, as Academic Director and Lead Instructor, he continues to be responsible for the University Extension program in brewing science of which the Masterbrewers program and the related Professional Brewers Certificate Program are the flagships, and he is active in the profession as a speaker and writer. His is a non-retirement. We are indebted to our students, at the university and in shorter courses, including those from unusual and even exotic backgrounds who, coming to the subject fresh have often provided us with new insights into brewing. These students are highly enthusiastic and dedicated women and men many of whom wish to enter the world of corporate brewing and others who are determined to build, own and run their own microbrewing enterprises. Their demands for knowledge of brewing has helped us to sharpen our focus on what to teach and how to best teach it, and accounts for some of our original editorial choices and some of the changes in this edition of the book. We are also grateful to the many brewing scientists and production brewers in various parts of the world who, over the years, have discussed brewing with us and generously provided of their time to show us their brewing operations. Equally, we are indebted to those experienced practitioners of the brewers art, who, while attending short courses for example, have often illuminated our science with their practice, and from which we have learned. Despite the help of all our colleagues and students the approach we have taken to the subject, the selection (and omission!) of topics and the view we have expressed are entirely our own and any errors are solely our responsibility. It is our intention and our hope that this book will provide a useful and practical grounding in the fundamentals of brewing science and the practice of brewing to all those who wish to acquire it. For those who will go further we have provided a reference list to texts, journals and proceedings as a starting point. Finally and foremostly, we thank our wives Sheila and Dorothy, to whom we dedicate this book, for without their support we would never have completed the task. Michael J. Lewis Department of Food Science and Technology University of California Davis California. USA TomW. Young School of Biosciences University of Birmingham Birmingham. UK November 2000

6 Units and conversion tables SPECIFIC GRAVITY CONVERSION CHART Values are at 20 C and rounded up. Plato=Degrees Brix=Cane sugar % w/w. Specific gravity Plato Specific gravity Plato vii

7 viii UNITS AND CONVERSIONS TEMPERATURE CONVERSION CHART Celsius Fahrenheit Celsius Fahrenheit Celsius Fahrenheit BEER VOLUME CONVERSION TABLE To convert the units in the left column to units in one of the right 5 columns multiply by the value in the table. Example-to convert Hectolitres to U.s. barrels multiply by hi = 1000 x = 852 U.s. barrels. Hectolitres U.S. barrels U.K. barrels U.S. gallons U.K. gallons Hectolitres U.S. barrels U.K. barrels U.S. gallons U.K. gallons 0.833

8 Units and Conversions ix UNITS AND CONVERSION TITLES Volumes 1 U.S. barrel = U.K. barrel = hi 1 u.k. barrel = U.s. barrel = hi 1 hl = 100 I 1 U.S. barrel of water weighs 258 lb. 1 u.k. barrel of water weighs 360 lb. 1 hi of water weighs lb. Weights 1 metric ton (tonne) = 1000 kg = lb. 1 u.k. ton (ton) = 2240 lb. 1 Zentner = 50 kg 1 kg = lb. 1 lb. = kg English traditional cask volumes 1 Butt = 3 barrels = 108 gallons 1 Hogshead = 54 gallons 1 Kilderkin = 0.5 barrel = 18 gallons 1 Firkin = 0.25 barrel = 9 gallons 1 Pin = barrel = 4.5 gallons Yeast pitching rate 1Ib./U.K. barrel of pressed yeast = 0.3kg/hl = about 10 million cells/ml Pressed yeast is about 20% solids Yeast slurry is about half the solids content of pressed yeast Carbon dioxide in beer 1 g carbon dioxide in 100 ml beer = 5.06 vol/vol 1 vol carbon dioxide/vol beer = 0.198g/100ml = 0.198% w /v Alcohol (Ethanol) in beer Alcohol % by weight = 0.79 X alcohol % by volume. Alcohol % by volume = x alcohol % by weight

9 x UNITS AND CONVERSIONS BARLEY AND MALT MEASURES country U.K. and South Africa Barley quarter Barley bushel Malt quarter Malt bushel Australia and New Zealand Barley bushel Malt bushel U.S. and Canada Barley bushel Malt bushel Pounds (lb) Kilograms (kg)