"Delicate and delicious," declares the haughty French hostess of a BYOB tasting party for wine professionals in New York City, sipping a wine from Bordeaux. "Especially when you contrast it to the California wine," she snips, rudely pointing at my award winning Napa Cabernet Sauvignon, standing forlorn on the table.

As a native Californian, such was my crude awakening to the inherent prejudice against California wines on the East Coast. Many upscale wine stores carry very few California wines. Of those that do, you'd rarely see Napa Valley wines advertised in email newsletters or recommended by the staff.

Why this predilection for French wine? One lingering reason may be that it's hard to beat a millennium of savvy marketing, a branding campaign so strong and global, even the famous 1976 blinding tasting event between California and French wines in Paris (in which noted experts chose a Napa Cabernet as the winner) failed to generate the expected reversal of thinking.

True oenophiles (or anyone who appreciates a flavorful, richly nuanced glass of wine) understand and appreciate the value of wines from California's Napa valley in contrast to wines from France. In a word, this "value" is born out of Napa's unique terroir.

Great wine depends on great grapes, which requires suitable soils, climate, and weather conducive to producing a ripe, disease-resistant crop. The topography of Napa Valley, with its glorious mountains, protects vineyards from wind. Its warm, rain-free summers allow the grapes to continue to ripen on the vine until harvest, without fear of a rainstorm trashing them to the ground. Yet to me, it's Napa's unique soils that help produce opulent, complex wines with exciting nuances of texture and flavor.

Consider, for example, the diverse soils and award winning wines of Diamond Creek Vineyards. Al Brounstein, its late founder, started in 1977 with a 70-acre parcel of land on Diamond Mountain and smuggled vine cuttings from two premier cru properties in Bordeaux. Long before the concept of "micro-climate" and artisanal wines were popular, he identified three unique vineyard blocks by the differences in soil structure (gravel/sand, volcanic ash, red/brown color) and climate (ranging from sunny and warm to cold and shady). After experimenting with winemaker Jerry Luper, they soon discovered which soils and microclimate produced the best varietals.

Because of its volcanic activity and changes in sea level over the past few million years, Napa Valley soil is inherently rich, but sometimes drainage can be a barrier for producing the best wines possible. At a recent lecture in Manhattan, James Kennedy, one of the world's premier tannin chemists, spoke about a case study in Napa in which he helped a vineyard produce a more balanced and award winning wine simply by working within the vineyard to improve irrigation techniques.