It is unlikely that the first Europeans to reach California had complex, layered and characterful pinot noirs from small, boutique wineries on their minds. But some of the early settlers' frontier spirit remains in Sonoma county, the larger, more geographically diverse wine-producing cousin of neighbouring Napa.
While the latter makes up the bulk of California's wine exports, Sonoma's reputation - forged over a century and refined over the past 30 years - is held in equal, if not higher, esteem by many American sommeliers.
This year's crop looks likely to add to that reputation, being equal to that of 2012's record bumper harvest growers are reporting mid-harvest.
Given the different conditions that many of Sonoma's vineyards and wineries operate under, it is perhaps not surprising that many of the wines - from varieties as diverse as pinot noir, chardonnay, pinotage and that old California staple, zindfandel - exhibit amazingly complex and layered flavour profiles.
"Within the US, Sonoma county has a very high reputation, especially from the regions of the Russian River Valley, the Dry Creek Valley, for example, the coastal sites. Those are an easy sell - sommeliers love these wines," says Debra Meiburg, a master of wine, a Sonoma native, and one of Hong Kong's best-known wine authorities.
Sonoma's marine-influenced Mediterranean climate and balanced physical geography are ideal for growing grapes in some places, but more of a challenge in others. These attributes also contribute to diverse growing environments, so that a range of varieties are produced throughout the county, much more so than in most appellations.
Reds include not only pinot noir, but also cabernet sauvignon, merlot and syrah, and whites include chardonnay and sauvignon blanc.
"Sonoma is definitely more varied than Napa, which is moulded around one large valley and the microclimates on their hills on either side of the valley," says Meiburg. "Sonoma has many valleys, and many small mountain regions, all of which are intensely affected by the ocean."
The most notable difference between Sonoma and its better-known neighbour is in the soils and weather. Napa has much less coastal fog influence and that affects daily temperatures, making Napa slightly warmer. The larger county to the south has soils that are more volcanic in nature, as opposed to the tectonic seabed plate that makes up most of western Sonoma county.
Another frequently made comparison is with the climate of Burgundy, but the terroir is different. What lies underfoot leads to a pleasing diversity in Sonoma wines. Given the high levels of seismic activity in northern California, the soil is immensely varied, sometimes differing even from plot to plot, and vineyards here deal with everything from gravelly soil in areas such as Alexander Valley, to volcanic-laced, clay soils in Chalk Hill.
Vineyards found in valley areas are fertile and loamy; those at higher elevations deal with rocky and well-drained soils.
"I see the relationship as one of admiration and respect for what each other has achieved in the world of wine, viticulture and food," says Bob Cabral, winemaker at the prestigious and critically lauded Williams Selyem Estate winery.
The relationships between vineyard owners and winemakers, some of which stretch back decades and do not necessarily place profit as the priority, also allow for a deep understanding between grower and producer.
With an average climate not dissimilar to Burgundy, grapes such as pinot noir and syrah thrive, but the climatological differences found within the county mean that there are variations - in the warmer northern appellations of Sonoma, such as Dry Creek Valley and Alexander Valley - hotter-climate grapes such as the Bordeaux varietals and zinfandel do equally well. This gives rise to the description of Sonoma as "Europe in a county".
Chardonnay does incredibly well in northern California, and no more so than in the cool-climate areas of Sonoma. Ramey Wine Cellars produces some world-class chardonnays and winemaker David Ramey calls his wines "neoclassical".
"We utilise classic French cellar techniques on California's consistently ripe fruit. In general [Sonoma] is cooler because it's closer to the Pacific Ocean, so it excels in early season varieties like chardonnay and pinot noir," he says.
Most of the winegrowers and winemakers are family enterprises with relatively small parcels of land and limited case production. There are old families who have been growing grapes and making wine in Sonoma for decades - largely Italian names, such as the Seghesio Family Vineyards, which went from a bulk winery in the 1950s to ultra-premium by the turn of the century.
"The soul of Sonoma lies in its family-owned boutique wineries," says California Vintage's Susan Darwin. The wine bar is at the forefront of promoting Californian wine in Hong Kong, and Darwin is an ardent supporter of California's lesser-known wine-growing regions.
"In Sonoma there are countless opportunities to spend time with the owners and crafters of the wines that one will taste. These experiences truly bring the wines to life. To a great extent, I believe that this is due to the county's agrarian roots," Darwin says.
There is a great emphasis on quality and a spirit of independence among the winemaking community, says Fort Ross Vineyard and Winery's Linda Schwartz, whose vineyards make up part of the newly created Fort Ross-Seaview AVA.
"This is an area of independent farmers, away from the conveniences of modern living and used to solving problems," she says.
"In the coastal vineyards, the extreme climate requires a frontier spirit, perseverance and a healthy dose of the rejection of reality. Without the need for conformity or societal acceptance, there is a tendency towards experimentation, and some novel stylistic approaches have evolved as a result.
Fort Ross produces some excellent wines under very trying circumstances, where the strong winds, fogs and temperature variations of the Pacific coast, along with rainforest-like levels of precipitation, conspire to make life as hard for the winemakers as possible.
Producing single-vineyard, cool-climate estate-grown pinot noir, chardonnay and even a pinotage, these fantastic wines are the result of a labour of love.
To the northwest of this rugged place lies the Alexander Valley, and Silver Oak Cellars. The winery's Daniel Baron worked on Petrus' 1982 vintage, so it is safe to say that he knows a little about making a good wine, and he exhibits the same passion and intensity that so many of his colleagues in this part of the world do.
His winery's Alexander Valley 2008 cabernet sauvignon uses grapes from a variety of sources throughout the valley.
Aged half and half in new and once-used American oak barrels, the 2008 cabernet sauvignon exhibits a great tannic structure, and the grapes produce rich, full-bodied wine.
The wine region is one of the warmest areas in northern California, but a huge swing over the course of a day means temperatures can drop drastically, affecting the ripening process over the growing period and giving rise to this unique expression of the grape.
Now the world is waking up to what those in the county have known for decades. "I believe Sonoma county is on the cusp of becoming a household name, like Napa, around the world within the food and beverage and wine communities," says Williams Selyem's Cabral.
"Our goal is to produce food-friendly wines that represent the very best quality from specific vineyard sites." While Cabral's wines do not come cheap, they represent some of the best iterations of pinot noir to be found in Sonoma.
Like all good things, Sonoma's reputation - gently understated but full of quiet confidence - has taken time to flourish.