California's Sonoma county emerges as a premium wine-growing region

(SCMP) - 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."