Thomas, a 19th-century American bartender and man about town, is a kind of Shakespeare of the cocktail world: the details of his life are sketchy, but the importance of the work he left behind demands that we study him. That work is found primarily in his 1862 tome How to Mix Drinks, or The Bon Vivant's Companion, the world's first compendium of mixed drinks. Before Thomas, no one had bothered to write down drink instructions on cocktail napkins, let alone in book form. These days, though, anyone who's serious about cocktails eventually works his way back to this Old Testament of tippling.

One such aficionado is the cocktail scholar David Wondrich, who has written extensively about spirits for Esquire and other publications. In his new book, Imbibe!: From Absinthe Cocktail to Whiskey Smash, a Salute in Stories and Drinks to "Professor" Jerry Thomas, Pioneer of the American Bar (Perigee, 2007), Wondrich takes the Jerry Thomas pilgrimage ten steps beyond what your average tippler would, beginning wiith fleshing out the life story of the libation wizard and then dissecting and interpreting many of the recipes he left behind. Along the way, Wondrich leads readers down many a beguiling side path, expounding on various histories and mysteries central to the barman's trade. It's no wonder that Thomas is still shaking things up.

How do you go about researching the life of a little-known 19th-century figure like the bartender Jerry Thomas? There can't be that much information out there.

No, there's not. They didn't have diaries. There aren't memoirs about them by their kids; just a lot of newspaper stuff and city directories. What I did is I built a chronology and kept revising it as I got new information until I got a framework that was solid. Once I had that, I read travel accounts of the places he was, to fill in the background. Doing that, you read hints that you didn't first recognize as hints. You realize, Oh, that's why he was there. This is what was going on. It's a complicated process, and in the end you don't have that much. But at least I got a full picture of his life.

Did you make any breakthroughs?

Yeah, I found a few really good things. Just by chance, I was looking through a trade journal from the 1870s for the liquor trade, and they had a long article on his bar and his liquor cellar. It talked about how popular his bar was and how important and how much money he was making. That told me the kind of things that he was mixing into his drinks. Also, I found an interview with him toward the end of his days, from the 1880s. And there were a lot of obituaries.

Obviously, he was well enough known to command all those death notices.

Oh, he was very famous, but not famous with the general public. He was famous with the sporting fraternities, as they called themselves: the club men, boxers, baseball teams.

How much experimentation went into putting together the book?

I tested every drink. Some of them repeatedly. Most of them repeatedly. This is over the course of years, and some of them I'd been testing and working up over time. Others, I found new recipes and sorted them out and tried to get them to be balanced drinks.

Did you test them at home?

At home, yes. I have a house full of booze. There was a whole section of Thomas's book that I had to remove because it was far too long: punch bowl drinks. Those I tested for large groups of people, frequently in backyards, at weddings and press events. The polling process was very informal. My friends are a fairly sporting group and willing to try punch. I made 40 different kinds of punch at least. But the cocktails I'd also try out on people at the drop of the hat.

Jerry Thomas boasted that he invented various drinks, like the tom and jerry and the blue blazer. But basically you debunk his claims one by one. Did he invent any cocktails?

(Laughs) He must have. In the last interview I have with him, he made this very astute comment that made me think he wasn't a total bullshit artist. He said, "I've invented lots and lots of drinks. The hardest part is finding a name for them, and that's the most important thing for a drink." And he's completely right. It's easy to mix a couple thises and that's, but to make an actual drink out of it that people will drink and pass around, it has to have a little backstory or a handle. He clearly had some experience with it. I just think people would ask him, and what was he going to say? "No, I didn't invent it"? It's not good for his PR. And he wrote the book! He put it down. He probably believed he had as much claim to the drinks as anybody.

That's the story in your field, isn't it? Disputations on everything: who invented the martini and where the term cocktail came from. Is that frustrating to you that you can't get to the bottom of so many major questions?

It used to be. Now I've come to accept it as being the nature of the field and sort of the beauty of it. There's an endless historical game. I'll never find the origin of the martini. It was not recorded in the journals of the time. People didn't get interested in the histories of these drinks until the 1890s.

Some people say the sazerac was the first cocktail, but in your book you refute that completely.

No! It wasn't. It's not possible. It's absolutely not possible. Myth is so powerful with this stuff. I've been yelling my fool head off about the manhattan's being invented by Lady Jennie Jerome [Winston Churchill's mother] for at least five or six years. There's a story that the manhattan was invented by her. It appears in the New York Times from time to time. Totally wrong. Easily disprovable. But people get into it. They like the stories. I think there are better stories out there, unrecorded, that are also actually true.

What's your favorite story?

My favorite story I came across in researching the book was in the New York Herald. It concerns the contest of cocktails held at the New York Hotel sometime in the 1860s, where an Irish peer met a Mr. Tracy from Buffalo at the bar, and they were both large men who liked to drink. They got into a disputation about their capacities and said, "All right. Tomorrow we'll have a contest." Panama Joe Fernandez was the bartender, and he made whiskey cocktails for them. He made them two at a time; they drank neck and neck until Mr. Tracy finally retired. The accounts are disputed. It was either 35 or 45 cocktails per person. Afterward they sat down to dinner, had a bottle of champagne and a little bit of port, and went to bed. Mr. Tracy was not seen again for two days. The Irish lord went on his merry way.

Robert Simonson writes the wine column "In the Cellar" for the New York Sun. He has also written about wine, food, and spirits for Salon.com, Culture and Travel, Time Out New York, and Wine Spectator.