Key Points:

"You should write about Sonoma," suggested the editor.

"Where?"

"You know, that upstate Californian wine region, next to Napa Valley?"

No, I didn't actually. But that's what you get for being a wine philistine.

Having washed up in San Francisco, it did seem rude not to take the 101 Highway north for a scenic 90-minute drive to Sonoma County.

I've barely gotten over the childish thrill of driving across the Golden Gate Bridge when we are criss-crossing the lavender, poppy and mustard fields that lead to what was, in fact, California's first wine-growing region.

Squashed between the cool Pacific Coast to the west and the baking Mayacamas Mountains to the east, Sonoma County is home to almost 27,000ha of vineyards and more than 250 wineries. Its unique topography and meteorology means the entire region is a patchwork of individual areas - or American Viticultural Appellations - each with their own combinations of soil, rain and sun that allow certain grape varieties to grow well.

But unlike its bigger, brasher neighbour, Napa, this sleepy Californian town was slow to bite the tourism apple.

Which can be a positive thing: the Sonoma vibe is more laid-back, almost hippyish, and its natives are the sort of friendly folk who know they've got it good.

It's hard to believe we're in the same state as Disneyland and the Hilton sisters.

Glen Ellen is a pin-prick on the vast Californian map but it looks as if it was plucked from a film set. Our accommodation is the chintzy Glenelly Inn, the kind of place that Martha Stewart would stay if she was in town.

But America's queen bee of homemaking probably wouldn't relish the communal breakfasts the way I do: each morning owner Kristi produces such delightfully bizarre fare as blueberry ricotta bread pudding with warm cherry sauce and an oddly delicious salsa souffle. But all that fresh country air gives me an appetite and I eat like a woman possessed. Besides, I tell myself, I need to line my stomach for the day's wine consumption.

Our first stop is the Sebastiani Vineyard where members of the same Tuscan family have produced wine for more than 100 years.

A stroll around their vast property shows that well-preserved grape juice has been kind to them. They've also reproduced a slice of the old country and the lush vines, olive groves and mission-style buildings could almost persuade you it's Tuscany or Provence; only the occasional palm tree reminds you it's not.

These days the family produces about 300,000 cases a year, most of which is chardonnay, cabernet sauvignon and that most Californian of wines, zinfandel.

The knowledgeable John Calmeyer leads us through the Sebastiani back catalogue and very quickly the full-bodied 2005 zinfandel becomes my new best friend.

Because it seems so environmentally unfriendly to spit out a decent mouthful of wine, I don't - which means that after an hour, my merlots merge with my pinots and I can't detect a raspberry, black cherry or nectarine note to save myself.

Much later, we call into the Jack London Village, named after the region's best-known son. The County is, in fact, awash with references to the writer: there's the Jack London State Historic Park, the Beauty Ranch and the Wolf House restaurant.

The Jack London Village showcases the region's many artisanal cheese, bread and chocolate producers that these days seem to attract as many headlines as the winemakers.

Next up is the nearby Benziger Family Winery. From the moment you walk up the pot-holed, tree-lined path, you know you're in for a treat - and an education. Here, organic is so last year: as our entertaining guide tells us, the biodynamic approach to viticulture means shunning conventional farming methods and embracing a self-sustaining ecosystem.

Knowing Benziger's wine won't sully my lips with pesticide residue makes the hippy shtick worth it, as does the ripe, fruity qualities of their 2005 Oonapais cab sav. At the obligatory tasting, I'm again drawn to the zinfandels but this time, I play the game and hoick (most of) it into the bucket. Here they take the snobbery out of wine tasting, patiently answering the dim questions a couple from New York seem compelled to ask (their inquiry as to whether biodynamic wine is less fattening than regular wine has us sniggering into our pinot). The fact you're not made to feel guilty if you leave without buying anything is also a sign of how mellow this wine region is.

The next day we decide to give the wineries and redwood forest a miss and head to Napa Valley to find out what all the fuss is about.

In Napa, wineries litter the landscape - think Martinborough plus much, much more - and it's quite a bit shorter on charm than its rival. This town is all about the mighty greenback and Highway 29 comprises one long stretch of signs advertising wine-tasting times, spas, expensive restaurants, and vineyard tours that you can take by railway, balloon and even helicopter.

Its saving grace is the huge Dean & Deluca deli, the first west coast branch of the New York favourite. I drink one of the best coffees I've had so far this trip and greedily stock up on their black and white cookies I developed a serious addiction for when I was last back east.

After a quick detour to empty our wallets at an outlet clothing mall, we scurry back to Glen Ellen and our slice of Californian paradise. It may have more of the barefoot, flower-child vibe than I was expecting but this pretty wine village is one of the United State's greatest hidden treasures.

Sharon Stephenson was a guest of Air New Zealand (www.airnz.co.nz) and The Sonoma County Tourism Bureau (www.sonomacounty.com)