ROSLYN, S.D. (AP) -- Like so many tiny towns across the Midwest, Rosyln was shrinking.
It was the 1990s and there seemed to be little hope of reversing the trend and attracting people to this community, which until then had been known only for being home to Myron Floren, accordionist from "The Lawrence Welk Show."
Which is why a consultant told Roslyn's leaders that the best bet for reinvigorating their community -- population 200 -- was to come up with something unique, something to set the town apart.
Eyes turned to Lawrence Diggs, a San Francisco transplant known around locally as "The Vinegar Man."
"Someone looked at me and said, 'Well, he's the most unique person here,"' Diggs recalled.
And so was hatched a plan to turn one man's passion for vinegar into a community revival project.
On a flight to Japan, Diggs, a passionate vinegar expert, consultant and author, took some table napkins and scribbled out a business plan for what would become the International Vinegar Museum.
Town leaders went for it, and Diggs' museum opened in 1999 in a New Deal-era brick building on Main Street. Residents went for it, too, joining together to host an annual International Vinegar Festival.
This weekend marks the community's 11th such festival, which features a parade, entertainment, vinegar tastings and the crowning of the 2010 Vinegar Queen.
If use of the word "International" seems a bit bold, Diggs notes that the museum not only features vinegars from every continent, but also has drawn visitors from every continent. Plus, "you've got to set yourself up to be the top dog."
"If you're a little mouse, you have to roar," he said.
Diggs first began exploring vinegar's use and history while studying food science at the University of San Francisco during the early 1980s.
He couldn't find a book on the topic, so he eventually compiled his research into a reference book, "Vinegar: The User Friendly Standard Text Reference and Guide to Appreciating, Making, and Enjoying Vinegar."
By 1989, Diggs was looking for a quiet place to do some research and write. He stumbled onto Roslyn, initially thinking it would be his getaway. But he quickly made the town his home base and has never looked back.
"I came here and the people were so nice to me here, that I thought, 'You know, it's quiet here. Why do I have to go back to San Francisco?"' he recalled.
Vinegar, a term derived from what the French call "vin aigre," or sour wine, develops from fruit or other starch-based consumables as part of a natural process in which sugars ferment past alcohol into acetic acid. Vinegar is primarily used in cooking, but it's also a natural preservative and cleaning agent.
And Diggs was on to something.
Until the '70s, vinegar was mostly white. But during the past 30 years, it has benefited from the gourmeting of the American diet. Today, balsamic is practically passe and artisanal varieties have become common, particularly during the past five years.
"I've seen honeydew vinegar, I've seen apricot vinegar," says Amy Albert, senior associate editor at Bon Appetit magazine. "I've seen chestnut honey vinegar, and many of them are organic."
As the American palate has become more sophisticated, home cooks have developed a greater appreciation for the role of acids such as vinegar.
"Acidity is a cook's trump card," Albert says. "Even if you can't taste the acidity in a dish, it's often what brings flavors together at the very end of cooking."
At the museum in Roslyn, more than 300 varieties of vinegar line the shelves, and panel displays educate on vinegar's history dating back to ancient Babylon, the home- and factory-based methods of producing it, organisms that help convert the sugars, and vinegar's true and perceived health benefits.
Visitors also can also eye paper made from vinegar and ceramics colored with it, but the main attraction is the tasting bar.
Tastings begin much like attending a winery tour, as Diggs pours a sample and suggests looking for color, clarity and "legs." But sniff from a distance.
"In wine, you kind of stick your nose in the larger glass," Diggs said. "Well, if you did that with vinegar, unless you're trying to clean your sinuses, it probably is counterproductive and it would be just too overpowering."
And instead of taking a sip, the process involves dipping a long cotton swab into the vinegar, touching it to the center of the tongue and pressing the tongue against the roof of the mouth.
These days, Diggs, 62, spends less time at the museum and more with his consulting business, Vinegar Connoisseurs International. He appears at chefs' conferences, teaches food and culture classes, and helps companies and organizations as far away as Kazakhstan launch vinegar operations.
The museum even produces its own balsamic vinegar under the brand IVM, the museum's initials, and is considering branching out into a white balsamic, possibly even a corn vinegar.
Diggs said he'd like to see Americans follow their European counterparts and develop a tradition of making their own vinegar at home.
If you have a half bottle of leftover wine, skip throwing it out and pour it into a jug to let it age, he said.
"That will be your house vinegar now," he said. "That's going to be a better vinegar than you're ever likely to buy."
If you go: The museum at 502 Main St. in Roslyn is open 10 a.m. to 6 p.m. Thursdays, Fridays and Saturdays from June 1 through Labor Day.