Jason Tesauro, right, brought wines from A to Z to his latest Grapetionary event, which took place last month in Potomac, Md., and entertained about 80 guests. (Michelle Frankfurter)

More than 1,300 varieties of grapes are used around the world to produce wine. Dedicated wine fiends may be able to experience most of those over a lifetime. Jason Tesauro would like us to taste an alphabet’s worth in a single fascinating evening.

He calls it Grapetionary, an A-to-Z exploration of the world of wine that combines ampelography (the study of grapes) with geography. It’s educational and fun — emphasis on fun.

Tesauro, 44, is co-author of “The Modern Gentleman” and sommelier and brand manager for Barboursville Vineyards in Virginia. He thought up Grapetionary while flipping the pages of Wine Grapes, an encyclopedic reference written by Jancis Robinson, Julia Harding and José Vouillamoz. Think of it as the Oxford English Dictionary of wine grapes.

“I was going through the book page by page, and I realized there were a lot of grapes that sounded interesting but not very delicious,” he told me. “And there were some that were interesting and delicious. I thought, what a great party these would make. And I love a theme party.”

Tesauro unveiled Grapetionary in June at the Atlanta Food and Wine Festival. He repeated in October at the Potomac, Md., estate of technology entrepreneurs Ken and Kavelle Bajaj for about 80 guests. The event was much more than just a wine tasting: Dinner was cooked by Masseria chef Nicholas Stefanelli, who closed his restaurant for the evening. (Two days before the party, Masseria was awarded a Michelin star.) Tesauro and David Kurka, Masseria’s wine director for the al fresco event, selected the wines.

Tickets cost $275 a pop, with a few auction-item sales benefiting the neonatal intensive care unit at MedStar Georgetown University Hospital. The extravaganza at the Bajaj estate may become an annual affair; chef Robert Wiedmaier of Marcel’s has already committed to cook next year. Tesauro also is planning a Grapetionary in California next year with Randall Grahm of Bonny Doon Vineyards, who has been working to expand the diversity of grape varieties in the Golden State’s vineyards.

The wine list at this year’s event spanned aglianico to zibibbo. The event would not be easy to replicate at home, even without a Michelin-starred chef whipping up dinner. “It took me three months to assemble the wines for the first Grapetionary and six weeks for this one,” Tesauro told me. Filling out the alphabet was not easy. “Thank goodness for Greece and Turkey,” he said. Their indigenous grape varieties accounted for a few challenging letters of the alphabet. Italy’s grape diversity also helped, providing several wines to match Stefanelli’s Italian cuisine.

Masseria sommelier David Kurka pours wine for Grapetionary, a dinner and tasting at the Potomac estate of Ken and Kavelle Bajaj last month. (Michelle Frankfurter)

The Q posed a dilemma. Only two grapes in Robinson’s tome start with that letter. One of them is Quebranta, the primary grape in the Peruvian spirit pisco, so Tesauro added a cocktail to the menu. The most difficult letter to fill was Y, but he eventually found a Turkish white make with Yapincak, from Pasaeli winery in the Turkish province of Thrace. Yapincak is described in Wine Grapes as “a minor Turkish variety” known for red-flecked berries that became a nickname for freckle-faced girls. More ominously, it is best valued for its leaves, used in stuffed grape leaves, a popular Turkish appetizer.

For this dinner, Tesauro offered only one U.S. wine, the 2015 Barboursville Fiano Reserve. No surprise, perhaps, given Tesauro’s affiliation with the winery, but there was no complaint from any of the diners, including me.

“I wanted to challenge the guests,” Tesauro said. “They drink a lot of California already. Let’s show them something else. If you’re open to a wine from Virginia, you’re also open to a Saperavi from Georgia or an Uva di Troia from Piemonte.” In all, the wines hailed from 12 countries.

Even for a jaded wine fiend like me, there were some surprises. A 2014 Verdeca from Masseria Li Veli in Puglia, the heel of Italy’s boot, was a vibrant, fruity white that cut through the cool night air and the richness of the food like a laser. And a 2015 rosé from Spain’s Basque region, the Ameztoi Rubentis Txakolina, made from a grape called Hondarribi Beltza, was an energetic revelation, perhaps the most convincing argument I’ve tasted that rosé should not be relegated to a summer patio.

I encountered an old favorite: the Kerner, from Stiftskellerei Neustift Abbazia di Novacella in the Alto Aldige region of northern Italy. And I made a new friend: the racy, flirtatious Viña Mein Loureiro from Spain’s Ribeiro district.

Best of all, I spent an enjoyable evening with like-minded oenophiles and an engaging tour guide leading us on an exploration of the world of wine.