Before the international beer cognoscenti were hip to the smoked lagers of Bamberg, Bob and Ellie Tupper had discovered the Gouda-like quality of the Bavarian town’s Aecht Schlenkerla Rauchbier. They’d developed an appreciation for the hand-pumped real ales of England, the distinct Kölsches and Altbiers of Rhineland, and the tart lambics of Brussels long before such brews became mainstays of American beer nerds’ “yeah, of course I’ve had that” lists.

These are just a few of the bragging rights the Bethesda couple has accumulated from more than 20 European beer trips since 1978. By phone midway through their latest six-week sojourn, Ellie, 63, and Bob, 67, describe the scenes at spots they’ve visited in England—the Wellington Pub in Birmingham, a beer festival in Plymouth, the Greenwich Union in London—with the spirited yet didactic rhythm of someone dictating an observation just crafted to perfection in his head.

They recount two days in Belgium from the same trip: one spent hunting for a bar they’d first visited two decades ago, only to find that the building housing it had been condemned, and another in which Bob walked more than 10 miles searching for off-the-beaten-path beer gems in Ghent.

If that sounds like a lot of effort to find the perfect pint, well, it is. Ellie, a production editor at the American Society for Microbiology, and Bob, a history teacher at the Holton-Arms School, have visited 18 European countries, several of them multiple times, in pursuit of new brews. Three-plus decades of research and travel left the Tuppers with a unique body of knowledge and experience, which they’ll tap in a self-published book this fall. Tentatively titled Drinking in the Culture: Tuppers’ Guide to Exploring European Beers, it will highlight the culture, history, and top beer destinations of 24 cities from Edinburgh to Vienna.

The duo’s interest in beer goes back to Bob’s student days at Hamilton College in upstate New York, but not in the way you might think. During a visit to Bob’s frat house, his then-13-year-old brother spied a beer-can pyramid and wanted to build his own. “He wanted me to drink so he could collect the cans,” says Bob.

So Bob soon started his own collection, which grew to some 2,000 cans before he decided it would be more fun (and take up less space) to collect only the memories of finding and drinking new beers. Ellie, whom he met and married when she attended Kirkland College (Hamilton’s now-absorbed school for women), rightly predicted that the new hobby would become a compulsion and decided she should get on board. Since then, the couple has tasted and taken notes on more than 25,000 beers.

Their first entry, logged in 1979 at Brasserie Henri Funck in Luxembourg, reads, “Bob: Tastes like beer. Ellie: Yes, it does.” Their palates have since become more sophisticated. Today, a standard entry details when and where they had the beer and includes a full description of how it looks, smells, and tastes. They record any available specifications, such as ingredients and alcohol content, and rate each brew using their own devised scale for quality and trueness to style, not just personal preference. In an era in which practically everyone’s a beer critic thanks to sites like Beer Advocate and Ratebeer, the Tuppers’ studious approach to beer isn’t out of place. But they were uber-nerdy about beer decades before being a beer nerd was hip.

When they aren’t traveling, the dedicated drinkers still average two to three new beers a day. “You don’t get to 25,000 by taking nights off,” Ellie says. They buy most of their specimens at favorite shops throughout the Northeast but also find them close to home. “The Washington area has become a great place to love beer,” says Bob. “The explosion here is something I didn’t expect to live long enough to see.”

He’s often had an up-close seat at that revolution. For nearly 30 years, he’s hosted beer-tasting events at Dupont’s Brickskeller (now the Bier Baron), which he and Ellie began visiting weekly in the mid-1970s.

When the Brickskeller decided to hold its first beer seminar in 1985, long before anyone thought “beer” and “seminar” could be uttered in the same breath, the bar immediately looked to the Tuppers for help. “We wanted to show how we could use the bar as an educational tool,” says former owner Dave Alexander. “We’d see [the Tuppers] sniff and swirl the beers around in their mouth. Ellie has an amazing ability to describe flavors, and my father-in-law thought Tupper could pull off a lecture since he was a teacher. It was the missing link.”

After three days at the University of Maryland library reading everything it had on beer and brewing—which wasn’t much at the time—Bob became the Brickskeller’s resident expert. He spent a few years delivering presentations himself, and then stepped back to become the official master of ceremonies, interviewing the field’s most esteemed figures—pioneers like Anchor Steam owner Fritz Maytag and beer writer Michael Jackson.

As craft breweries began opening in the D.C. area, the Brickskeller events evolved to include locals like Lost Rhino Brewing Company co-founder Favio Garcia, who met the Tuppers in 1994 when he worked at the original Bardo Rodeo brewpub in Arlington. “Ellie takes a back seat at the tastings, but she seems just as involved in the preparation,” Garcia says. “They know all the beers and the brewers and the stories, and she’s got all the facts straight.”

That quest for knowledge fuels the Tuppers’ passion for beer. “Brewers I’ve met are every bit as smart as the scholars I work with,” says Bob. “We’ve been able to learn from so many hundreds of them over the years,” Ellie says. “It’s been a lifetime of picking up really interesting information.”

By 1994, that learning, and the experience of tasting more than 6,000 beers, led them to decide to make a brew of their own. They wanted to create an ale that was lagered, meaning it had fermented several weeks longer than usual, for smoothness and balance. They would add whole-flower Mount Hood hops, for a fresh, spicy bitterness. The beer would be bottle-conditioned and “Kräusened” to be naturally carbonated and ensure a clean flavor. The result would be something that, for its time, was completely unique.

Although they had a clear idea, the Tuppers lacked the skill or equipment to execute it, so they approached Old Dominion, then in Ashburn, Va. It produced Tuppers’ Hop Pocket Ale and, later, Hop Pocket Pils until 2007, when the brewery was sold and relocated to Delaware. During that time, Tuppers’ Beers won several medals and critical acclaim. The line was briefly revived at St. George Brewing in Hampton, Va., from 2010 to 2013, although the Tuppers and the brewery have since parted amicably. Finding a new host brewery has been difficult: The couple owns the trademark, but thanks to a state law, distributors in Virginia retain the rights to the brand.

But Hop Pocket’s brewing run was long enough, and the beers popular enough, to fund the Tuppers’ daughter’s undergraduate education. Ellie and Bob donated the rest of their brewing proceeds, more than $120,000, to nonprofits that serve the homeless.

“They’re very much about giving back,” says Laurie Tupper, 28, currently a Ph.D. candidate in statistics at Cornell University. “I’m really proud of them for approaching it that way: They don’t want to just be critics; they are creators. And they use it to connect with people. Beer is the common ground. You barely speak the same language, but by God, you know a good lager when you taste one.”

The Tuppers brought Laurie along on their extended quests as she was growing up, despite social norms that might suggest not taking kids on beer odysseys. “It was a great experience to go to all these places,” she says. “You show up, look at the monument, and then go around to all these tiny little towns and talk to the people who live there.” Still, reading books in a pub wasn’t always her choice activity. “There were parts of it I didn’t enjoy, but I wouldn’t say that is more true of the beer focus than if my parents were into golf vacations or whatever else,” she says.

The Tuppers acknowledge that their hobby has some drawbacks, like how it’s limited their opportunity to do other things. “If we were here in Ghent and not interested in beer, we’d have seen the two art museums already,” says Ellie. And for years they traveled cheaply, sleeping mainly on trains or in places where “one of us could sleep while the other one stayed up to hit bugs with a shoe,” Bob says. Now they “pay other people to kill our bugs” and stay in Hiltons. Another downside, of course, can be the beer itself, although only “a fairly small percentage have been unpalatable,” Bob says. “A larger, but still relatively small percentage have been boring.” Still, the Tuppers have given fewer than 3 percent of the beers they’ve tried their combined top rating.

Back home, the Tuppers are collaborating with Lost Rhino to brew a series of beers celebrating Bob’s 94-year-old mother, Laura “Lolly” Gilbert Tupper. Mother Tupper’s Back-of-the-Cupboard Imperial Rye IPA, to be released in November, will be 9.4 percent alcohol by volume and have 94 IBUs (a measurement of bitterness in beer). Next year, it will be 9.5 percent alcohol and 95 IBUs, aging along with its namesake.

A trial batch of a lower-alcohol version was brewed in June and served as the Tuppers’ 25,000th logged beer. Appropriately dubbed “Tuppers’ 25K,” the rye pale ale featured a variety of American hops, including their favorite: Mount Hood. Garcia, who brewed Hop Pocket at Old Dominion, describes the 25K as a “nice, strong throwback ’90s ale.” Put another way, the beer was the perfect choice for their milestone, a reminder that some obsessions only deepen for the better.

Photo courtesy of Bob and Ellie Tupper

Correction: Due to an editing error, this post originally credited the wrong photographer for the photo, which is not by Tom Cizauskas.