This book arises out of our experiences and careers in teaching and researching into brewing science and technology. These careers, at the University of California, Davis, USA and the University of Birmingham, UK, to date amount to a joint total of more than 45 years. The approach taken to the subject, the selection of topics and the views expressed are entirely our own and any errors and omissions are solely our responsibility. We are grateful to 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. We are indebted to our students who, coming to the subject fresh have often provided new insights into brewing. Equally, we are indebted to those experienced practitioners who, in attending short courses, have often illuminated science with practice. In more recent years in courses at the University of California we have had the pleasure to help to instruct newcomers to brewing from less traditional backgrounds. These women and men, highly enthusiastic and dedicated to the concept of developing and running their own microbrewing enterprises in North America, have brought their own demands in search of knowledge of brewing. Their needs have increased our resolve to publish this book.