Here’s a question for wine buffs only: Name a pair of white and red wines from anywhere in the world that express the vinous extremes of flavor, weight, tannins, and overall personality. Until last week, my candidate for the ultimate lightweight wine would have been a sprightly, low-alcohol, pale-as-springwater German riesling. At the other extreme, carrying the maximum punch and depth of flavor, I’d have picked a brawny, big-alcohol, inky Australian shiraz.

That was before I attended two midweek lunches, each of which showcased wines that forced me to revise my nominees for the extremes. And, unlike the wines above, grown a hemisphere apart, the vineyards of these wines are only a half-day’s drive from each other in France. The first event, at the BLT Fish raw bar, was a Bastille Day bash hosted by growers of muscadet from vineyards around Nantes, where the Loire River prepares to flow into the Atlantic Ocean.

In an era of look-at-me wines, modest muscadet is too often the wallflower at the wineshop dance. Unoaked and shy of fruit, it’s a wine that tends to go unnoticed as white-wine seekers gravitate toward more glamorous examples such as New Zealand sauvignon blancs, assorted chardonnays, the aforementioned German rieslings, or even Loire brethren such as Sancerre or Pouilly-Fume. Yet none of those wines could have danced with a bivalve as gracefully as a Muscadet I tried last week – Domaine des Herbauges “Clos de la Senaigerie,” from the Cotes de Grandlieu ($9.49) – served with a plate of four raw oysters. The brininess of the oysters matched and melded with the saline note in the Muscadet so fully that both might have come out of the same shell. Other whites may seem to be made for raw oysters, but in my mouth most are too assertive. What works best is the leanest possible quaff, jingling with minerality, that comes closest to tasting like the earth-born, first cousin of seawater. No other wine fits that profile like muscadet.

If muscadet “floats like a butterfly,” to invoke the young Muhammad Ali’s self-description, then the red wine of Cahors is the heavy puncher in the Mike Tyson mode. Located in rugged country north of Toulouse, Cahors is the one and only French appellation in which the primary grape is Malbec, locally called Auxerrois. So potent is the wine made from this grape that, in the old days at least, it was called the “black wine of Cahors.” The generally thinner red wines of Bordeaux were once strengthened with transfusions of concentrated Cahors.

Unlike its Bordeaux counterpart, the less-developed wine culture of Cahors went dormant after phylloxera killed off its vines in the 1880s. In recent decades, a few adventurous newcomers have brought new energy to Cahors, none more so than Alain Dominique Perrin, who rose from marketing assistant to chairman (now retired) of Cartier Inc., the French luxury goods firm. In 1980, Mr. Perrin bought the derelict 15th-century vineyard Chateau Lagrezette, hired the rising young wine-making consultant Michel Rolland, and audaciously set out not merely to revive a vineyard, but to create a world-class wine. “Cahors is really in the middle of nowhere,” Mr. Perrin said at lunch at Eleven Madison Park last Tuesday. “You don’t got there by choice.”

Wouldn’t it have made more sense to put down wine roots in, say, Bordeaux, where prestige did not have to be created from scratch? “Alain knew that if he bought property in Bordeaux, he could make a good wine, but never the best,” said Florence Delattre, Mr. Perrin’s companion, who was seated next to me at lunch, “but he felt that in Cahors he could make the best.” Mr. Rolland was not enthusiastic about signing onto the project. “‘Come on, nothing is impossible for a guy like you,'” I told Michel,” Mr. Perrin said. Mr. Rolland rose to the challenge. “At first, we were making the wine in the local cooperative, but that made Michel crazy, and he said, ‘Why don’t you build a winery?’ And so I did.”

For all its strength and sinew, old-fashioned Malbec typically lacks finesse and its tannins can be gnarly. Mr. Rolland has worked minor wonders in smoothing out the rough edges of Lagrezette without sacrificing its power. This is wine for wool-sweater weather, not for a muggy summer afternoon. Still, various bottlings of Lagrezette accommodated themselves well to the wild mushroom soup and then to the fennel and coriander Muscovy duck breast served at the restaurant. To my taste, however, the wines stubbornly resisted harmonizing with a trio of funky artisanal cheeses. Or maybe it was vice versa.

Mr. Perrin happily announced that, after years of effort, he has succeeded in convincing the bureaucrats of the Institut Nationale des Appellations d’Origine (INAO) to allow him, or any other Cahors vintner, to put “Malbec” on Lagrezette front labels, just as is done on versions from Argentina, where Malbec sales are booming. The wines of Lagrezette now number more than half a dozen, ranging from bargain-priced Castel Montplaisir to the flagship “Le Pigeonnier,” a wine whose 2001 vintage Robert M. Parker’s Wine Advocate recently rated 95 points.

Ms. Delattre had been appalled, when we first chatted, that I wasn’t aware of her companion’s history with Cartier. She told me of his pride in creating Les Must de Cartier, a line of basic designs more accessible than the name Cartier normally implies. I confessed that my eye once lingered on a Les Must man’s wristwatch featured in an Air France seat-pocket catalog. But, while I’ll hang on to my battered Timex, I do plan to acquire, in time for winter dining, a stash of what can fairly be called “Les Must de Lagrezette.”

RECOMMENDED WINES

MUSCADET COTES DE GRANDLIEU SUR LIE, SERGE BATARD, DOMAINE LES HAUTES NOELLES, “LES GRANGES” 2002 ($10.99) Imported by Daniel Johnnes, wine director of Montrachet (profiled last week in this column), this edgy, mineral-driven white is to the French taste, but lessso to palates weaned on lush fruit and an extra tad of sugar. It’s a taste worth acquiring for shellfish lovers. The length of this wine’s name is in inverse proportion to its weight. At Crush Wine Co., 153 E. 57th St., 212-980-WINE.

MUSCADET SEVRE ET MAINE SUR LIE, LUNEAU PAPIN 1997 ($19.99) D.Y.A. (drink youngest available) is the usual rule for muscadet, but if the rules always held, wine would be a far less interesting subject. This one, from a very ripe vintage, keeps a pale young color, but it has deepened to resemble a lightweight white Burgundy, perhaps from St. Aubin or Rully. The cost is comparable. At Chambers Street Wine, 160 Chambers St., 212-227-1434.

CHATEAU DE LAGREZETTE 2001 ($21.95) The basic wine of the property, exhibiting all the dark power of Cahors and Malbec, albeit sculpted and polished to smoothness. This wine will outlast most of us. If a hunter ever brings me venison fresh from the forest, this is the wine I’ll open. At Sherry-Lehmann, 679 Madison Ave., 212-838-7500.

CASTEL MONTPLAISIR 2001 ($10.99) Lagrezette, as well as the touch of uber-consultant Michel Rolland, are here bottled at a bargain price. This has a lovely, iron-tinged aroma not unlike a ripe Nuits-Saint-Georges from Burgundy. In the mouth, the wine is powerful, though lacking the depth of higher-priced Lagrezette. This wine should make believers of those who think the French have fallen behind in the value race. At Martin Brothers, 2781 Broadway, 212-222-8218.