Then it dawned on me that I was thinking in terms of buildings instead of wine. Opus One, the winery - the unique, jewel box-like confection of cream-colored limestone that literally rises out of the earth in the center of Oakville's vineyards - was completed only in 1991, just in time to process that year's harvest. Until then, the wine had been made just across the road at the Robert Mondavi Winery.

So, for its first twelve years, Opus One was out of sight, without a home to call its own. But the wine was certainly a presence in itself - well known to collectors and connoisseurs at home and abroad, and impressive from the outset. When the 1979 and 1980 vintages - boldly priced at $50 per bottle when most other highly regarded California Cabs were selling in the $15 to $20 range - were simultaneously presented in 1984 at initial release festivities in New York City, one critic, echoing the sentiments of his colleagues, exclaimed "Opus won!"

There is a reason for the high price tag beyond the cachet of the Rothschild name combined with the pioneer reputation of the Mondavi family: Opus One is a very expensive wine to produce, and has been since day one. "The standard is not to be excellent here, it is to be perfect," co-Winemaker Tim Mondavi declares matter-of-factly. No compromises are made, no corners cut. Opus One is meticulously "hand massaged," with frequent topping of barrels and six rackings during its 18 months in barrel, making it extremely labor intensive. The wine is moved only by the gentle force of gravity; mechanical pumps are banned. In the first-growth tradition, the $700 French barrels are never reused. And, at a cost of more than $29 million, the Opus One Winery ranks as one of the world's most expensive single-product facilities.

Opus One created its own market niche as the first, true ultra-premium wine when it was launched in 1984. Before its introduction, there existed a void in this category, not only in the United States but around the world. Today Opus One still dominates this particular niche, at least among American wines. Given the fact that at 30,000 cases (up from the inaugural 2,000 cases) it's not an impossible-to-find wine, its mastery is its crowning achievement.

Opus One was the brainchild of Baron Philippe de Rothschild, proprietor of first-growth Château Mouton-Rothschild in Pauillac, and Napa Valley's visionary winemaker Robert Mondavi. The baron broached the idea to Mondavi when the two first met in Hawaii in 1970. Within ten years, the world's first international joint venture in wine was a reality, with Mondavi's son, Tim, and Mouton's winemaker, Lucien Sionneau, equally in charge of crafting the winery's one and only wine.

When Sionneau retired in 1985, his roles at Mouton and Opus One were assumed by Patrick Léon, whose contribution to the evolution of the style of the wine has been significant. Together with Tim Mondavi, the co-winemakers embraced the high-density planting methods favored by the Bordelais, resulting in five to six times more plants per acre than was the California norm. According to Mondavi, at higher densities, the vines produce smaller berries with higher skin-to-juice ratios and more intense flavors and aromas.

In the winery, skin contact during fermentation, which extracts flavor and softens tannins, was gradually extended each year, so that by 1985 it had been doubled from the ten-day period of the 1979 vintage to 21 days. The 1996 Opus had 37 days of skin contact. The aging regimen also changed over time, from 24 months in new French oak for the first Opus to 19 months for the 1996 version, resulting in the more accessible, although certainly ageable, Opus of today.

Sadly, the baron, who died in 1988 at the age of 86, did not live to see the winery's completion. His only child, Baroness Philippine de Rothschild, took over the family business, and today shares ownership of Opus One with the Mondavis, led by 86-year-old Robert Mondavi.

In celebration of the winery's 20th anniversary, the Mondavi family and the baroness threw a two-day party in mid-October that dwarfed any social event the Napa Valley had ever seen. "Lavish" does not even begin to describe the scope of the event, centered around a gala reception for 650 guests at the Oakville winery the first day, followed the next day by an extraordinary black tie dinner-dance for 240 guests at the winery that featured congratulatory messages from President Clinton and André Parant, the French Consul General based in San Francisco. (Less grandiose celebrations took place in New York, Paris and London later in the year; more parties are in the planning stages.)

San Francisco-based event designer Joe Cunningham tented 10,000 square feet of the winery's parking lot in glittering, otherworldly opulence to accommodate the glamorous crowd, a fascinating mix of celebrities, politicos and Napa Valley's winemaking elite. Chef Michel Cornu, one of the region's most sought-after caterers, prepared dinner, which featured escargot, caviar and smoked salmon hors d'oeuvres, and copious quantities of Champagne Veuve Clicquot, followed by lobster and Dungeness crab, breast of wood pigeon with foie gras and poussin accompanied by wines from Mouton, Mondavi and Opus One.

As the celebrants crowded the dance floor, gyrating to the band's highly amplified melodies, I came away with the most memorable sight of the evening: the elegant, yet eminently vivacious baroness, in her red silk dress and pearls, performing a mean boogie to the pulsating strains of the Village People's "YMCA." Not particularly out of character for this former actress, who traded a life on the stage for Mouton-Rothschild only in the 1980s.

Tasting 20 Years of Opus

The elegant, cream- and pale yellow-appointed salon, the winery's most formal space, was the setting for the late-morning tasting of every Opus One ever made, including the 1998 barrel sample. "The 21st vintage is in the cellar now," Tim Mondavi informed the select group of 30 international wine journalists, explaining that the Opus harvest had been completed just eight days before. Mondavi presided over the event, joined by his father and the baroness, who displayed her penchant for dramatic entrances by arriving just tardy enough to create a flourish.

All but the 1998 (which was drawn from barrel) were poured from magnums and decanted just prior to the tasting. Each Riedel glass (Vinum-416/15, for the record) came with its own glass watch-face cover to preserve the aromas.

This wasn't a blind tasting; each wine was clearly identified and separated into four flights, which Tim Mondavi believes represent the four evolutionary stages of Opus One - a theory proved essentially correct by the tasting. The early wines - 1979 through 1983 - were lean and elegant in the French style, evidencing the strong influence of Mouton-Rothschild. From 1984 on, each flight revealed increasingly fuller-bodied wines exhibiting greater opulence and ripe fruit, tempered or enhanced by the peculiarities of the particular vintage. He referred to this progression as "a continued march toward richness, ripeness and bigness."

His father chimed in, explaining that they are striving for friendly, concentrated wines. "We don't believe in powerful, aggressive wines," the family patriarch said, "but rather wines that display elegance, harmony and finesse, and that are best suited for mealtime."

While Opus One is a cabernet sauvignon-based wine, the addition of other Bordeaux varieties in the blend contributes appreciable nuances and complexity. It's therefore instructive to note the percentages of the other components in each case, usually cabernet franc and/or merlot, with malbec first showing up in 1994, and petit verdot making its debut with the 1997 vintage.

If one wanted to duplicate the tasting with a 750-ml bottle of each wine, gathering the 18 released bottlings from merchant and auction sources would cost in excess of $4,200. Add to that the time spent and expense incurred in persuading the winery to part with a bottle each of the two unreleased wines. The prices noted below for vintages 1979 through 1993 are those quoted in the 1999 catalog of Bel-Air/Twenty Twenty Wine Merchants in West Los Angeles. Release prices are indicated for the 1994-96 bottlings. There is no price information for the two yet-to-be-released wines. My ratings are based on the BuyLine's 100-point scale.

Flight 1

1979 (blended with 16% cabernet franc and 4% merlot) - $350: Wonderfully evolved, intense, fragrant nose of cedar, black fruits, smoked meat, leather and brown spice. Sweet and luscious with soft tannins and brimming flavors, yet supremely elegant and complex. Bordeaux-like in its balance, depth and richness. Drinks fine now. Tim Mondavi's favorite of this flight. Score: 92

1980 (blended with 4% cabernet franc) - $350: A bit more Californian in style with bigger tannins and body than the 1979, yet still supple. Aromas of celery root, tar and shy fruit. Ripe and concentrated, offering cherry-cassis fruit, yet lacking a fine acid balance. Score: 87

1981 (blended with 7% cabernet franc) - $295: Swinging back toward the Médoc with a leaner body and restrained elegance. Fragrant but subdued aromas of spicy cedar and black fruits; sweet, cherry-cassis fruit accented by chocolate and dried herb notes. Tasty, but not very complex. Score: 87

1982 (blended with 16% cabernet franc and 2% merlot) - $295: Pleasant, very slightly earthy scents of cherry-cassis, brown spice, cedar and dried herbs. Notes of chocolate and herbs mingle with spice and generous cherry-blackberry fruit on the palate. Firm but supple tannins. Score: 90

1983 (blended with 13% cabernet franc and 7% merlot) - $265: Fragrant, appealing nose exhibiting subtle notes of forest floor, cedar and mushroom accenting ripe black fruits. Sleekly structured with good acid balance, delicious fruit and a subtle, peppery flourish in the finish. A charming wine from a difficult vintage. Score: 91

1984 (blended with 3% cabernet franc) - $255: Peppery nose with distinct cedar notes. Succulent, round and smooth with abundant ripe cassis, anise and peppery spice. Firm tannins matched by fine concentration and depth of fruit. Robert Mondavi's favorite of this flight. Score: 90

Flight 2

1985 (blended with 6% merlot and 4% cabernet franc) - $255: Fragrant, appealing, moderately herbaceous, Médoc-like nose of bell pepper, cassis, cedar and chocolate. Elegant and well structured, exhibiting balance and finesse with gobs of sweet, luscious, succulent cassis tinged with tobacco leaf. Score: 92

1986 (blended with 9% cabernet franc and 4% merlot) - $255: Somewhat restrained, yet intriguing nose of dried herbs, mineral, cedar and black cherry. Intense flavors of mocha and black fruits, vanilla and coffee bean. Bold, delicious and exquisitely balanced. Score: 92

1987 (blended with 3% cabernet franc and 2% merlot) - $255: A spectacular wine offering forward, appealing scents of raw red meat, black pepper, clove and black cherry-cassis. Huge on the palate, yet finely balanced with luscious, rich, deep, extracted black fruits accented by notes of dried herbs and leather. Score: 94

1988 (blended with 13% cabernet franc and 2% merlot) - $225: Muted nose of cedar and cassis tinged with spice. A victim of an off vintage; a little ragged around the edges with modest, slightly raisiny fruit. Score: 84

1989 (blended with 2% merlot and 1% cabernet franc) - $225: Another weak vintage that produced a wine with more fragrance than palate presence. Interesting for its forest-floor earthiness and hints of brett. Nevertheless, Tim Mondavi liked it best within this flight. Score: 83

1990 (blended with 10% cabernet franc and 3% merlot) - $255: Complex, fragrant, appealing scents of cherry-berry fruit, mineral, bell pepper, violets, smoke and vanilla. Lush, almost jammy flavors of blackberry and cassis tinged with toasty oak. Tim Mondavi noted that more time is needed to pull all of its elements into a harmonious whole. Score: 86

Flight 3

1991 (blended with 5% cabernet franc and 1% merlot) - $245: Fragrant, appealing scents of violets, mild cedar, red meat and black fruits, accented by dried herbs, smoke, roasted almond and anise. Quite spicy and delicious with bright, vibrant cassis fruit that's deep and nicely concentrated. A full-bodied, well- balanced, profound expression of cabernet. Score: 91

1992 (blended with 8% cabernet franc and 3% merlot) - $200: Shy nose of black fruits and cinnamon-clove spice. Enormous palate presence and massive, ripe tannins - a veritable wall of sweet fruit, chocolate and smoky oak. A wine with great concentration and potential, requiring several more years. Score: 91

1993 (blended with 7% cabernet franc and 4% merlot) - $200: Exotic nose of vanilla, geranium, sandalwood, mineral and black cherry. Luscious and succulent with medium-full tannins, the flavors replicate the nose and are deep and concentrated. A distinctive and delicious Opus. Score: 93

1994 (blended with 4% cabernet franc, 2% merlot and 1% malbec) - $95 on release: Fragrant, appealing scents of black fruits, dried thyme, cinnamon-clove spice and French oak enhanced by notes of tobacco leaf and leather. Smooth, round and elegant, yet generous, delivering absolutely delicious, spicy, plummy fruit tinged with dried herbs that lingers into the extended finish. Opulent Opus at its best. Score: 94

1995 (blended with 7% cabernet franc, 5% merlot and 2% malbec) - $100 on release: Slow-to-open nose of berry-cassis, toasty oak, vanilla, caramel, clove and lead pencil. Even bigger than the 1994 with extracted, concentrated blackberry-cassis fruit and medium-full, supple tannins. Mouth-filling with plush textures, this is a massive, intense Opus with excellent aging potential. Score: 95

1996 (blended with 8% cabernet franc, 3% merlot and 3% malbec) - $125 on release: Expansive, aromatic nose of dusty herbs, clove, sandalwood, ripe black fruits, leather and toasty oak. Deep, ultra-ripe black fruits are accompanied by a wisp of Médoc-like green herb, with flavors that show excellent concentration and avoid any suggestion of being overripe. A bigger style than bottlings up to 1993 with medium-full tannins and considerable extraction that will require several years of cellaring. While both the 1994 and 1995 vintages exhibit similar levels of concentration, this complex, exquisitely balanced wine best illustrates the evolved Opus style. Score: 96

Flight 4

1997 (blended with 8% cabernet franc, 5% merlot, 4% malbec and 1% petit verdot) - $N/A: Even more impressive than the fabulous 1996, offering wonderfully fragrant aromas of licorice, vanilla, toasty oak, clove and ripe blackberry-cassis. The vanilla dominates the palate now with blackberry-cassis extract and brown spice swirling below. Silky smooth and seamless on the palate with flavor-enhancing acidity, medium-full, supple tannins and a firm, tight structure. (Release date: Fall 2000). Score: 97

1998 (blended with 7% cabernet franc, 1% merlot and 1% malbec and petit verdot) - $N/A: In its preliminary stage of development, it shows generous cassis fruit that is still a bit grapy and sweet, along with a good dose of oak spice and caramel. "It's in its adolescent rage now, but should follow the '96 and '97 nicely," Tim Mondavi predicted. Score: 95

Based in San Francisco, Contributing Editor Steve Pitcher is vice president of the Vintners Club and president of the local chapter of the German Wine Society.