Mine is The Theory and Practice of Brewing Illustrated by William L. Tizzard, printed in London in 1846. It’s a brilliant book by one of the first brewers to really delve deeply into the science of brewing. He was a bombastic writer who castigated his colleagues who brewed by rote without truly understanding what they were doing. There is a chapter entitled “East India Pale Ale” which inspired our beer of the same name. It was a gift from the famed brewpub pioneer David Bruce.
Technology Brewing and Malting by Wolfgang Kunze
After that, two highly respected:
Malts and Malting by Briggs
Brewing Yeast and Fermentation by Boulton & Quain
Origin And History of Beer And Brewing From Prehistoric Times to the Beginning of Brewing Science And Technology by John P. Arnold (1911).
There’s another book called Let There Be Beer by Bob Brown (1932) I came upon not too long ago, which contains, I believe, some of the most lyrical writing on beer I’ve ever read. Really wonderful.
The books I turn to most would be:
The Essentials of Beer Style by Fred Eckhardt
Great Beers of Belgium by Michael Jackson
Joy of Homebrewing by Charlie Papazian
The various tomes in the Classic Beer Style Series
Here are two unfamiliar and one familiar book to answer your question about beer reference books:
Michael Jackson’s Pocket Guide to Beer (Simon and Schuster, numerous editions) Still the first place I turn for information about an unfamiliar brewery or about places to drink in cities I’m visiting.
William L. Downard, Dictionary of the History of the American Brewing and Distilling Industries (Greenwood Press, 1980). An excellent concise excyclopedia of American breweries and distilleries. An up-to-date version of this book would be welcome.
Allen Winn Sneath, Brewed in Canada (Dundurn Press, 2001): A very good concise history of Canadian breweries and the beers they made.
Martin Morse Wooster
In my “Lager Library,” the most popular books are:
Simon & Schuster Pocket Guide to Beer by Michael Jackson
Michael Jackson’s Beer Companion
Classic Stout & Porter by Roger Protz
The Good Beer Book by Timothy Harper and Garrett Oliver
Beer Basics by Peter LaFrance
Windows on the World Complete Wine Course by Kevin Zraly
Champagne by Serena Sutcliffe
Jim Murray’s Complete Book of Whiskey
Spirits & Cocktails by Dave Broom
Michael Jackson’s Complete Guide to Single Malt Scotch
The Martini by Barnaby Conrad III
The Complete Book of Mixed Drinks by Anthony Dias Blue
The Harvard Student Agencies Bartender Course
The Complete Book of Cocktails & Punches by Sue Michalski
Professional Guide to Alcoholic Beverages by Robert and Kathleen Lapinski
The Bar and Beverage Book by Costas Katsigris and Mary Porter
I still probably refer to Michael Jackson’s books the most. The Beer Companion and New World Guide to Beer are used all the time, even though some of the information has become outdated.
As I typically focus on British topics, Roger Protz’s stuff also gets a lot of use. I still use The Ale Trail from time to time. Given the frequency of my travel to the UK, it’s no surprise that I rely heavily on the CAMRA Good Beer Guide (I don’t always buy it every year, but do have the last 3 years including 2005). But I also really like the annual Good Pub Guide.
My favorite pub guide to London is out of date, but still quite valuable. It’s Peter Haydon’s Known Treasures & Hidden Gems: A Guide to the Pubs of London. It hasn’t been updated since 1996 but I still refer to it frequently. It’s among my most dog-eared and beer-stained books in my collection! His new book, The London Pub, is quite nice, but it’s less of a practical guide and more of a coffee table book.