(Wine-Searcher) - It's all about Napa when it comes to California's most expensive wines, but not exclusively about Cabernet.

While California lays claim to some of the world’s largest wine producers and big mass-market brands, the state is also home to a thriving industry of small-scale artisan producers and premium wineries.

Napa Valley, California's most prestigious and world-renowned wine regions, is home to the state's top-end producers. The focus is invariably on Cabernet Sauvignon, or the classic Napa Cab, therefore it is no surprise that this grape variety dominates our most expensive list. It would be natural, therefore, to assume that a Cabernet Sauvignon-based wine should take the winning podium; astonishingly, it's a Sauvignon Blanc.

Here is Wine-Searcher's Most Expensive California Wines list. It's not a list based purely on price – that would consist almost exclusively of Sine Qua Non wines, which are different each vintage, and therefore eminently collectible, often reaching outrageous prices in the secondary market. To be eligible for this list, wines had to have a minimum of four vintages available.

1. Screaming Eagle Sauvignon Blanc, Oakville

Initially released in 2010, Screaming Eagle's Sauvignon Blanc has quickly soared to the top of the rankings, with the wine now retailing at prices averaging $3706 (excluding tax).

The wine was originally created for a select few mailing-list customers and restaurants with only 300 bottles made. The low volume of production has stuck, with only two barrels of the 2013 vintage created. This scarcity has in part contributed towards its value and the Sauvignon Blanc now reaches prices above the estate's flagship Cabernet Sauvignon-based wine.

The Sauvignon Blanc grapes are grown on a tiny 0.8-hectare (2-acre) plot of Screaming Eagle's Oakville vineyard. This only came about by chance though, as no other grape variety was able to thrive in the tiny plot of clay terrain.

According to Leo Fenn III, founder and president of Cult Wine, the reason why Screaming Eagle's Sauvignon Blanc is the most expensive in the world is: "Supply and demand. It's traded among the wealthy who want the prestige of saying: 'I have one of the 300 bottles made.'"

2. Screaming Eagle Cabernet Sauvignon, Napa Valley

As Jancis Robinson puts it: "Screaming Eagle is a legend, and the legend is almost invariably told by people who have never tasted it." Robert Parker has largely contributed towards this legendary status after he first awarded Screaming Eagle's 1992 vintage Cabernet Sauvignon 99 points, calling it "one of the greatest young Cabernets I have ever tasted". Since then, the Cabernet Sauvignon has continued to score highly among the critics, and this is reflected in its $2890 average price tag.

3. Harlan Estate, Napa Valley

Property developer William Harlan bought his Oakville hillside vineyard in 1984 with a view to creating a California "First Growth". After clearing approximately 4 hectares (10 acres) for the planting of predominantly Cabernet Sauvignon, as well as Merlot, Cabernet Franc and Petit Verdot grapes, Harlan produced the estate's first commercially available vintage in 1990, releasing it in 1996. Decades on and the estate has expanded to encompass around 100ha of vineyard dotted across the Oakville hills.

Harlan attributes the complexity of the wine to the "wild lands surrounding the vineyards" in combination with "soils that are partly sedimentary and partly volcanic" and the "unusual diversity of aspect, with northern, southern, eastern, and western exposures". Five of the estate's vintages have now achieved 100 points from Parker, sending prices skyrocketing to an average of $825.

4. Schrader Cellars Old Sparky Cabernet Sauvignon, Napa Valley

Old Sparky (average price $731) comes from the Beckstoffer To Kalon Vineyard in Napa Valley, and is 100 percent Cabernet Sauvignon. Both the winery and the wine itself take their names from Founder Fred Schrader, better-known by his nickname "Sparky" from his younger soapbox derby racing days.

Beckstoffer To Kalon vineyard dates back to 1868 when pioneer Hamilton Crabb acquired the land. The vineyard was originally named for the Greek To Kalon, meaning highest beauty, and sits on north-south sun-exposed hillsides cooled by the coastal breeze. This together with the soil's high level of minerals and drainage are perfect for the creation of a Cabernet Sauvignon with intense crème de cassis, blackberry and toasted oak notes after aging in new French oak