Last week, I was a wine judge at California's Sonoma County Harvest Fair. At 8am on a foggy Santa Rosa day, I duly donned my white lab coat, introduced myself to the judging panel and waited for the pouring team to bring in our first flight of wines. Flight isn't a word one instinctively associates with wine, unless, like me, you have the cheerful habit of sipping your way through international airspace. In wine-speak, flight is a term used to describe a selection of wines poured and tasted in tandem, usually with the intent of evaluating one against the other. A horizontal flight is a range of wines with common characteristics, typically of the same grape variety, origin and vintage, such as a dinner series of six glasses of 2003 Bordeaux wines. Vertical flights are comprised of wines that are identical except they are from different vintages, although not necessarily consecutive years. When it comes to judging, flights are rounds in a particular competition class and can range from a few glasses to a daunting array in the hundreds. The Sonoma County Harvest Fair is open only to Sonoma producers so does not include wines from its friendly rival, Napa County. Laid-back Sonoma is often left behind when it comes to international attention because its winemakers and vineyard owners pride themselves on being more restrained and low-key than their flashier neighbours. One could say Sonoma's attitude is similar to that of Burgundy and Napa's grandeur is more in keeping with Bordeaux. While both Sonoma and Napa successfully grow the same array of grapes, Napa specialises in the cabernet blends of the famed Bordeaux region and Sonoma is markedly successful with the Burgundian variety, pinot noir. Sonoma County is immediately west of Napa County, with the Mayacama Mountain Range drawing a craggy line that divides the region in two. With gentle rolling hills, the meandering Russian River and ocean cliffs that plunge abruptly into the Pacific Ocean, Sonoma's vineyard districts are more distinctively delineated and climatically diverse than those of its rival, allowing for a broader range of wine styles. Sonoma's most well-respected districts are Dry Creek Valley, Carneros and my childhood home, Russian River Valley. The exceedingly warm Dry Creek Valley is famed for its outstanding zinfandel and the cooler Carneros district excels at pinot noir. My family home is in the heart of the Russian River valley - one of the most beautiful wine regions in the world - where vineyard-cloaked hills give way to ancient redwood groves and, ultimately, the ocean. Russian River Valley produces world-class pinot noir and chardonnay, many varieties of which are available via Golden Gate Wine Co ( www.golden gatewine.com). Judging these wines for a week was pure pleasure. Be sure to sip them both vertically and horizontally.