Come August, variety all but disappears from my lunch menu. I’m content to sit at the kitchen counter and eat a freshly made tomato sandwich on a slice of white bread, a ciabatta roll, or a plain bagel. Though easily dismissed as humble, it’s a seasonal dish that’s as intriguing, in its own way, as autumn’s white truffle risotto, although not nearly so expensive. Not just any tomato will do, of course. It has to be a Long Island or Jersey tomato, its color a deep and shimmery orange, fading to streaks of yellow around the shoulders (fully red tomatoes seem to lose their acid backbone). Sliced open, the local version’s smell and taste is as difficult to describe as it is distant from the standard supermarket excuse for a tomato. You’ll only know that it’s a product of favored earth in its prime season.

Because it takes to endless variation, a tomato sandwich resists flavor fatigue. Sometimes, the sliced fruit (yes, it’s classified as a berry) can lie on a thin bed of cucumber or arugula, or else directly on the bare bread. I dress it with just enough vinaigrette to work into the crevices of the tomato and mingle with its own juices. Next, I sprinkle some crumbled leaves from a dried oregano stalk or a few torn leaves from the basil plant in the kitchen window. Maybe, too, some sliced sweet onion or chopped scallions.

Curiously, I never thought about which wine, if any, might partner with a tomato sandwich, until last week. To explore the possibilities, I called Aaron Von Rock, the wine director at Telepan on the Upper West Side, a restaurant that focuses on pristine seasonal produce as well as artisanal wines. Would he be willing to join me in sorting through tomato and wine match-ups?

Mr. Von Rock eagerly accepted the challenge, even though he was leaving on vacation the next morning. Barely an hour later, the two of us were sitting at a corner table at Telepan, surveying assorted tomato dishes and an array of white and rosé wines (we agreed that red would be a mismatch).

With proprietor and chef Bill Telepan’s ultra-crunchy fried green tomatoes, we first sipped a Greek white wine, Tselepos Mantinia ($13 at Astor Wines), made from the moschofilero grape. The theory here was that a bright, fruity quaff from a country where tomatoes thrive might make the pairing click. “This wine seems almost to have a crunch to it, as if it could be seasoning the tomato,” Mr. Von Rock said. It was terrific with the fried green tomatoes and it percolated, too, with a dish of red, yellow, and purple heirloom tomato quarters, grilled eggplant, and buffalo mozzarella.

Next, we tried Étude Rosé of Pinot Noir 2006 ($20 at Zachys), a wine so beguilingly aromatic that Mr. Von Rock looked around and exclaimed, “Wow, I wanna be sure that we aren’t inhaling someone’s perfume.” The wine tasted as caressingly soft as it smelled, quite the opposite of the zingy Greek. It seemed to wrap itself around tomatoes I’d brought over from the Greenmarket, cut into wedges and untouched by herb, oil, or even salt.

Wines with big flavor volume seemed like a bad blind date to tomatoes, and to check out that proposition, I’d brought a white Chateauneuf-du-Pape “Les Sinards” 2005 from Perrin et Fils ($33 at Toast Wines by Taste) Sure enough, the mild-mannered tomatoes seemed to embitter this big, oaky, almost viscous white. A “palate coater,” as Mr. Von Rock said, it needed a dish that would do the same, like grilled salmon. At the other extreme from the Chateauneuf-du-Pape, a light-bodied Spanish “Las Brisas” Rueda 2006 ($8 at PJ Wines) tasted too thin with the tomatoes. The same was true of an electric New Zealand sauvignon blanc, the Terrace Heights 2006 Marlborough ($48 on the wine list).

Mr. Telepan stopped by our table and delivered his personal tomato wisdom: Summer tomatoes taste best when they’ve become very warm from, say, sitting in a car parked under the sun for a couple of hours.

Mr. Von Rock next poured an Austrian wine, Fritsch Grüner Veltliner “Steinberg” 2005 ($34 on the wine list). “Our kitchen will sometimes dress a salad with citrus and white pepper, and this wine is almost a vinous form of the same idea,” he said. Indeed, the Grüner Veltliner was at its best perking up the unadorned tomato wedges, as if it were vinaigrette. “It even has a saline element,” Mr. Von Rock said. With this wine, hold the salt.

Over the weekend, I continued my research at home. At the suggestion of importer Victor Schwartz, I tried an albariño from Rias Baixas on Spain’s Atlantic coast. It’s a wine whose citrus and honeydew flavors have a way of expanding in the mouth. This example, Burgáns 2006 ($12 at Gotham Wines), turned slightly bitter with a tomato sandwich, but the sensation was pleasant — “like an apple a few weeks before it’s fully ripe,” my daughter, Kate, said.

For a finale to this exercise, I poured a Delamotte Rosé Champagne ($68 at Garnet Wines): It is a noble wine, paired with a noble fruit of summer. But the taste of the tomatoes disappeared into the frothy texture of the wine.

The verdict: None of the wines I tried at Telepan or at home unlocked any explosive synergies with the tomatoes of summer. But lovely harmonies did occur, notably with the Tselepos Mantineia, the Étude Rosé, and the Burgáns albariño. Lively fruitiness, little or no oak, and medium body and acidity are the components that enable a wine to cozy up to a tomato sandwich.

If one last August heat wave comes, however, I think I’ll stick with a tall glass of ice water.