Approaching his 93rd birthday, Robert Mondavi remains the iconic figure of Napa Valley and, in fact, of all American winedom. The pioneering Mr. Mondavi’s impact on the wine scene ranges from inventing the wine style called fume blanc to creating the Napa “First Growth,” Opus One, in partnership with the late Baron Philippe de Rothschild. But while the nonoagenarian still stands tall, his family winery empire has stumbled. Badly executed overseas expansion and lackluster critical ratings for the wines took their toll. In 2004, the once-proud Mondavi empire was purchased by Constellation Brands, based in unsung Fairport, N.Y. Mr. Mondavi and his sons, Michael and Tim, once top operatives at the family winery, are out of the picture.

A few weeks ago, the winery put on its best face at Restaurant Daniel to celebrate what must be a bittersweet 40th anniversary of its founding by Mr. Mondavi in Oakville, Calif., the heart of Napa Valley. First came a pre-lunch panel discussion of “sense of place,” focusing on Mr. Mondavi’s prestigious 550-acre vineyard called To Kalon. Then came a blind tasting that showed, particularly in the case of four sauvignon blancs, how tricky wine identification can be.

The first wine, heady with the propulsive scent of grapefruit and freshly mown grass, was true to its region: Marlborough, New Zealand. It was Cloudy Bay Sauvignon Blanc 2002 ($26.99 at Mount Carmel Wines). But the second wine, flowery with low acids that made it pillow-soft, seemed like anything except what it turned out to be: Didier Dagueneau’s Pouilly Fume “Pur Sang” 2003 from the Loire Valley ($65 at Tribeca Wine Merchants). His whites, even when aged in new oak like this one, are usually animated by herbal notes and shivery acidity. What changed this vintage of Pur Sang was the brutally hot summer of 2003, which killed many thousands in France.

The third wine, true to fume blanc style, with citric, herbal, and pineapple notes underpinned by a touch of oak, was Mondavi’s own: Fume Blanc Reserve 2004 ($34.95 at Sherry-Lehmann). The final wine first struck me as tired and fruit-deficient, although it was rich in a lanolin-like oiliness, indicating a dollop of semillon in the blend. But then a range of mineral notes fanned out in my mouth on the long finish of this wine – just the opposite of lesser wines, which deliver a burst of forward flavor that quickly dissipates. This was Chateau Haut-Brion Blanc 2002, the most expensive wine among this quartet of whites ($195 at Sherry-Lehmann).

Wine-making at Mondavi has been directed since 1997 by Genevieve Janssens, who first came to the winery from France in 1978. A barrel sample of her 2005 Mondavi Cabernet Sauvignon Reserve brimmed with curranty fruit, wood spice, and potent but velvety tannins. It should become a classic.

With lunch, Mondavi’s library selection wines shone with chef Daniel Boulud’s dishes. A full-bodied, waxy-textured Fume Blanc Reserve 1994 was superb with roasted sea scallops. Of three Cabernet Sauvignon Private Reserve vintages accompanying Trio of Organic Veal, the star was the oldest: vintage 1978. Its aromas were ripe and sweet, its fruit still vibrant. Age had enriched this Private Reserve, not withered it.

No member of the Mondavi family was on hand for this event. But the best of their wines spoke for them.

MAKING MORE OF MOUTON CADET In 1930, decades before his Opus One partnership with Mr. Mondavi, Baron Philippe de Rothschild was faced with a disastrous vintage at his beloved Chateau Mouton Rothschild. Rather than bottle the wine as Mouton, the baron sold it off under a new label, Mouton Cadet (“Mouton Junior”). It sold so well that Mouton Cadet, sourced in later years from secondary Bordeaux sites, became a familiar brand in France and, since the 1960s, in America. For unadventurous consumers, Mouton Cadet has long been a safe buy in inexpensive Bordeaux.

By the turn of the century, however, Mouton Cadet was suffering from a case of the blahs. Too many under-$10 wines from other parts of France and the rest of the world provided more flair and flavor. Five years ago, Baroness Philippine de Rothschild, her father’s successor as president of the family wine business, decided to upgrade both the red and white Mouton Cadet. On a recent Tuesday, the chief executive of Baron Philippe de Rothschild wines, Xavier de Eizaguirre, showed off the results so far over lunch at Maloney & Porcelli. Pouring the 2004 white and 2003 red Mouton Cadet, Mr. Eizaguirre called them the first vintages in the “new style.” “We’ve tried to improve the fruit in two ways,” he said. “First, by doing more careful parcel selection with our 88 growers, and then by bottling earlier to better capture the fruit. And we have built a new winery so that we cut the time between the vineyards and the wine-making.”

A decision was made, however, not to make the wines taste oakier. “We surveyed the market, and super-oaky was not the answer,” Mr. Eizaguirre said. “Fruit was.” Neither red nor white Mouton Cadet is touched by oak.

The 2004 Mouton Cadet white, a classic Bordeaux blend of semillon, sauvignon blanc, and muscadelle, is ripe, fresh-tasting, and rounder in the mouth than previous versions. The 2003 Mouton Cadet red has also been plumped up. It’s even a bit chocolatey, yet retains the bedrock Bordeaux traits of restraint and balance. And, while these wines, widely available at about $8, won’t wow you, the blahs have been banished.