“This is all Barolo on the left. This is Barolo. This is Barolo. This is all Barolo. This is Barolo, too. This is Barolo, until here. Then these are Super Tuscans.”

That’s Enrico Farello, wine director at Barbetta, giving a tour of the cellar at the 100-year-old Italian restaurant where dining has never stopped being gracious. Here, Piedmontese cuisine is worshipfully served and eaten under a chandelier that once belonged to the Savoys. Barbetta knows Barolo. In fact, owner Laura Maioglio says she served Barolo when the great Italian red could hardly be found in New York.

“When I took over the restaurant in 1962, there was one Barolo on the market, a Fontanafredda, and that was it,” she said. “I had to bring in the rest. I brought in a Gattinara. I brought in a Barbaresco.”

Barolo and Barbareso are no longer hard to locate, not in stores and certainly not in the Barbetta wine cellars. They’re located in the basements of 323 and 321 W. 46th St., two of the four townhouses Ms. Maioglio’s father, Sebastiano, bought from the Astor family in 1925. In both cellar rooms, it’s a challenge to find a bottleneck not wreathed in the pink paper strip that designates a specimen from one of Italy’s great red wine DOCG regions. The nebbiolo grape rules Barbetta’s daunting wine list, just as surely as the House of Savoy once ruled Piedmonte. Barbaresco consumes three and a half pages. Barolo commands 11.

Ms. Maioglio is not shy about enumerating the glories of her restaurant, which she says served the first risotto, panna cotta, polenta, and tiramisu in New York. According to her, when Donato Lanati, the well-known Piedmontese oenologist, visited the restaurant in January, he said, “This is the greatest Italian wine list I’ve seen.”

Ms. Maioglio, a Bryn Mawr art history major, assumed control of Barbetta in 1962. Her succession was part of neither her nor her father’s plans. Sebastiano Maioglio founded the restaurant in 1906 in a space on 39th Street, not far from the old Metropolitan Opera. By the early 1960s, he was ready to unload it. His daughter, just out of college, had other ideas. She tracked down the buyer and — accompanied by a lawyer friend — convinced the man to renege on the deal.

Sebastiano was dismayed when he discovered the intrigue. “I was sentimental to a fault,” Ms. Maioglio explained recently. “He built this thing, it was in the family. Why sell it?”

She closed the restaurant for a year to execute comprehensive renovations. Sebastiano’s penchant for spartan décor was not at all shared by his offspring. Ms. Maioglio went on a buying spree, snatching up 18th-century Italian antiques when she could find them, replicating them when she couldn’t. She spent a year negotiating with the owner of a royal family palazzo in Turin for the aforementioned chandelier.

Ms. Maioglio’s comes by her grand outlook honestly. Pausing before a black-and-white 1958 photograph of the tiny Piedmonte town Fubine Monferrato, she pointed at a large, ancient building in the center of the town and said, “That is my window.” The window belongs to a roomy mansion that has been in the family since 1701. She visits regularly.

Wine vinified from Maioglio vineyards used to be served to customers on 46th Street. (The Gringnolino and Barbera she grows are now sold to a cooperative.) Barbetta has its own dedicated truffle hunters in Italy and, during truffle season, the prized white fungi are flown in weekly.

Despite the restaurant’s traditional Piedmontese menu, the wine list was once as French as Lutece’s. “Italian wines started coming to the U.S. in the 1970s, and by 1977 I made a decision,” Ms. Maioglio said.”If I’m going to tap all the great French wines, and all the great Italian ones, it’s going to be unmanageable. Let me concentrate on the Italian.” Soon, Champagne was the only French wine to be found at Barbetta.

Ms. Maioglio credits Leopoldo Frokic, the restaurant’s wine director until 2004, with making the list what it is today. She knew him only as the son of her buildings’ superintendent when, in 1997, he asked to be put in charge of Barbetta’s cellar. “I had about 300 wines. He expanded it in depth and breadth and everything,” Ms. Maioglio said. Mr. Farello came on in 2003 and worked at Mr. Frokic’s side for eight months. The new man felt quite at home among the Barolos, being Piedmontese himself.

“Enrico’s town is only 15 minutes away from my town,” Ms. Maioglio said. She recently flew back from Italy, where, she said, “I just saw his mother at the truffle fair.”