As a wine appellation, Napa Valley is partitioned into 15 sub- appellations, each claiming to possess such a distinct microclimate and terrain that its wines stand apart esthetically from its neighbors.

One is Rutherford, which covers nearly 7,000 acres stretching east and west from Highway 29 between Oakville and St. Helena. Within that block, 3,518 acres are planted to wine grapes, 71 percent of them cabernet sauvignon.

Rutherford has been celebrated for its savory and supple cabernet sauvignons since at least 1887, when Gustave Niebaum completed construction of the winery Inglenook. Since then, several other people instrumental in developing Napa Valley's wine trade have settled in Rutherford.

One of them was the late André Tchelistcheff, a Russian-born, Paris-trained chemist who joined Beaulieu Vineyard as a progressive and influential winemaker not long after the repeal of Prohibition.

Among other things, Tchelistcheff is credited with coining the term "Rutherford dust." The precise quote attributed to him is: "It takes Rutherford dust to grow great cabernet."

That seems pretty clear-cut: If you want to make great cabernet sauvignon in Napa Valley, you've got to get the fruit from vines grown in the immediate vicinity of Rutherford.

Vineyardists and winemakers in Napa Valley's other sub-appellations, such as Spring Mountain, Stags Leap and Yountville, may take issue with that.

For sure, the term "Rutherford dust" has acquired magical and romantic interpretations well beyond Tchelistcheff's straightforward and self-serving observation. Today, "Rutherford dust" has come to represent in the area's cabernet sauvignons such attributes as tannins as fine and fleeting as dust, a savory flavor suggestive of dry soil, and a spiciness akin to pie spices, all of which might well be news to Tchelistcheff.

A few months ago, the Rutherford Dust Society staged a blind tasting of 22 cabernet sauvignons made with grapes grown within the appellation. All were from 2008, the vintage in current release. They ranged in price from $26 to $200, averaging out at $96, for an idea of how highly regarded Rutherford is, at least by its vintners.

I went to the tasting looking for dust in any or all of its permutations. I didn't find it, though I could see how the generally gentle tannins of the wines, despite their youth, could be seen as wispy as light dust.

Instead, I found wines notable mostly for their generous and fresh cherry fruit, structures that were firm without being unforgivably hard, and an acidity surprising in the degree of its refreshing tang. Despite their youth, virtually all showed a carefully cultivated suppleness and equilibrium.

I found in several of the wines a thread I like very much in cabernet sauvignon, an herbalness suggestive of eucalyptus, bay leaf and mint.

Nevertheless, my favorite of the 22 wines wasn't one with much of that, though a seam of appealing herbalness did run through the wine. Instead, the Flora Springs Winery & Vineyards 2008 Rutherford Hillside Reserve Cabernet Sauvignon was rich with ripe Bing cherries, ending with a tanginess in the finish that begged for one more sip, then another.

In addition to its lush fruit, it struck me as the most complex wine of the day, with the most enduring length. It was aged entirely in new French oak, but the wood was integrated astutely, not at all jeopardizing the sunniness and juiciness of the fruit.

The grapes that went into the wine were grown in the northwestern reaches of the Rutherford appellation, on a slope at the base of the Mayacamas Mountains known informally as the "Rutherford bench." It's an alluvial area of gravel loam left by creeks flowing from the higher reaches of the Mayacamas range. Yields are low in the vineyard and berries are small, says Flora Springs winemaker Paul Steinauer.

Compared with earlier vintages of the wine, Steinauer said, he used more high-tech tools as well as old-fashioned hand sorting to end up with grapes that were precisely round and ripe, without blemishes or any vineyard debris getting into fermentation tanks. He also extended the time that the fruit was "cold soaked," a technique in which juice is left in contact with skins in hopes of extracting more flavor and color.

"The result is more color in the wine without as much alcohol and tannin. The wine is richer and fleshier," Steinauer said.

The closest he comes to saying whether the wine has any "Rutherford dust" is to refer to the wine's "trademark minerality" or "earth tone."

At $100, the Flora Springs isn't an everyday cabernet sauvignon. It's a holiday wine, best given to someone who is a keen fan of cabernet sauvignon and with the patience to lay it down for five to 15 years, though it's perfectly fine for drinking right now.

Flora Springs Winery & Vineyards

2008 Rutherford Hillside Reserve Cabernet Sauvignon

By the numbers: 13.8 percent alcohol, 347 cases, $100

Context: Winemaker Paul Steinauer says he likes the wine with "anything in the meat category," most especially game and steak. "But I've been known to drink cabernet with salmon as well."

Availability: The wine is sold mostly to restaurants, including the Supper Club and Matteo's in Sacramento, where owner Matt Woolston sells it at retail and on the wine list. It also is available at the winery's tasting room, The Room, 677 S. St. Helena Highway (Highway 29), St. Helena, open 10:30 a.m.-5 p.m. daily. It also can be ordered through the winery's website, www.florasprings.com.

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Longtime wine critic and competition judge Mike Dunne continues his relationship with The Bee as a contributing columnist to the Food & Wine section. His wine selections are based solely on tastings, judging at competitions, and visits to wine regions. Check out his blog at www.ayearinwine.com, and reach him at mikedunne@winegigs.com.

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