Of all the salespeople who ask you, “Need some help?” the one on whom you are most dependent is a wine seller. Not only must she pick up on your style of wine (which may actually diverge from your claimed preferences), but she must also guide you to a bottle which will match that evening’s dinner. And you’ll only know if she steered you right when the wine and food have been served.

I was on the phone last Thursday, scheduling an interview with Lee Campbell of Harlem Vintage, the wine salesperson I most trust to steer me right, when I overheard a customer say to her, “I’m having a dinner party tonight. The main dish is … “

“I have to go,” Ms. Campbell said, and clicked off. When she called back a few minutes later, I asked her what wine the customer had settled on.

“He wanted a red to go with baked chicken with rosemary and lemon sauce,” she said. “He’d already picked out a California cabernet sauvignon which would have been okay, but I had something in mind which I thought would be better without flipping all his switches. Whenever I hear lemon, I think acidity in the wine. American wines just don’t have it. That cabernet was going to be a little flabby with his rosemary and lemon.”

Her suggestions were two wines from Chianti. “One was Montesecondo, labeled Rosso Toscano even though it’s from Chianti. That name couldn’t put be put on the label due to some issues with the labeling bureaucrats,” she said.

“The other option was an Arcano Chianti Colli Senesi. Both these wines had the crispness that the lemon sauce will round out. The customer chose the Arcano because I think he was more comfortable with a wine actually labeled Chianti. People here trust me so much, and I feel, Why rock their boat unless it’s worth rocking?”

Sometimes wine salespeople “advise” in the form of making pronouncements. They impose their views. Others are lower-key – sometimes too much so. Ms. Campbell’s gift is to create dialogue with the customer, which she may initiate in ways that from others would be cheeky. I recently saw her do it by delicately peeking into the Citarella shopping bag of a customer who seemed indecisive as she stared at a wall of white wines at Harlem Vintage. “If I could see what you’re having for dinner, maybe I could help you,” Ms. Campbell said. And she did.

Ms. Campbell grew up in Poughkeepsie in a family with Jamaican roots. “I was always a sensualist,” she said. “Very tactile and sensory. And those are things that aren’t necessarily appreciated above all others in an immigrant family, even though my grandmother helped to start a major culinary school down there.”

Her career in wine, however, was unexpected. “I majored in political science at the University of Virginia with the intention of going to law school,” she said. “But then when I was ready to apply, I had a little breakdown. I didn’t really want to go to law school.”

Being an “idealist,” Ms. Campbell went to Washington, D.C., in 1994, where she worked for several people, including Daniel Patrick Moynihan. One evening, on her birthday, she convinced her boyfriend at the time to take her to Restaurant Nora, a pioneer in organic dining. “I spent a long time just reading the first page list of Nora’s food purveyors,” she said. “One day, I knocked on her door and asked, ‘Can you do something with me?’ I became Nora’s personal assistant for a year. And that set my food palate.”

Arriving in New York in 1997, Ms. Campbell, who is now in her early 30s, worked at a succession of restaurants, including Verbena, Union Pacific, and Gotham Bar and Grill. Though she logged kitchen time, her real talent was “front of the house,” where she could greet customers and manage staff.

“I was working for amazing chefs,” she said, “but the wine thing was hard coming. In the wine world, I didn’t see anyone who looked or acted like me.”

Still, Ms. Campbell felt that she needed to know more about wine: “It was practicality at that point, not passion.” She became a certified sommelier in 2000. After working briefly for a small wine importer, she signed on as a salesperson at Chambers Street Wines. “When I was thinking of going into law,” she said, “that only responded to my empirical side. Then I got into wine, and it also had the sensory thing. It was like switching from black-and-white to Technicolor.”

Last fall, she heeded a call to manage Harlem Vintage, which was opening at 2235 Frederick Douglass Boulevard. In a part of the city where wine has long been sold as an afterthought in liquor shops, Harlem Vintage is its first upscale shop. Rather than being shielded by bulletproof Plexiglass, as is typical in such uptown shops, Harlem Vintage’s sales counter has no barrier. Its eclectic selection of 400 wines, chosen by Ms. Campbell, even includes a “winemakers of color collection.” Saturday night wine tastings are lively affairs. And two nights ago, the winemaker of South Africa’s Indaba winery, Mzokhona Mvemve, dropped by Harlem Vintage for a tasting.

Celebrating its first birthday this week, Harlem Vintage has reached the top rung of the city’s wine boutiques. Ms. Campbell, with her warmth and expertise, is part of that success. Her counsel is trusted and, thanks to a cache of treats behind the counter that she dispenses liberally, even customers’ dogs look to her expectantly.

“After much struggling and tussling, my parents let me do what I really wanted to do,” she said. “So I hope that seeing me, other people from disenfranchised communities will know they also have options to do what they want to do. They may feel they are expected to be teachers or go into business, even though they really love wine. When they come into Harlem Vintage, they can say, ‘I see someone who looks like me who has done it.'”