To the shiny golden heart of the New World. Ever since the Judgment of Paris in 1976, when a Chardonnay and Cabernet from the Napa Valley beat the socks off esteemed French wines in a blind tasting, California has built on its reputation as a source of outstanding bottles (as well as a sea of mass-produced stuff, vast as the Pacific). Geography has given Northern California a clutch of close but distinctive regions. How to capture the flavour in five days?
Day 1, First Stop Cool Carneros:
Forty minutes north-east of San Francisco, the houses dribble out into a broad sweep of vineyards backed by low, velvety hills. This is Los Carneros - on the same latitude as Sicily, but cooled so effectively by the chill air from the California Current that it's perfect for Chardonnay and Pinot Noir. At Saintsbury, Dick Ward and David Graves make some of the most thrilling Pinot that has crossed my lips to date, made from the three Dijon clones they have planted at Brown Ranch, the vineyard that makes their finest wine. Please, Jim Nicholson, can you beg some for Ireland? The winery - galvanised American barn with riotous flower garden and good paintings - is like Ward: confident, urbane.
On to Napa, the ritziest region, and Robert Mondavi, the visionary who made it so. The first to champion stainless steel and French oak back in the 60s, the first to invest lavishly in marketing and research, he is still, at 86, a dynamo: just back from an elephant-riding holiday in Bhutan. The sheer scale of the Mondavi HQ at Oakville is alarming. The winery, styled like a Franciscan mission church, has a car-park bigger than the average vineyard. I'm looked after by a "wine educator" - one of a team of 30. She is worried that I'll miss the guided tour across the road at Opus One, the celebrated joint venture between Robert Mondavi and the late Baron Philippe de Rothschild. All very imposing - with the same icy perfection as Mouton. More Franco-California fusion at Clos du Val, established in Stag's Leap in 1972 by a partnership involving Bernard Portet from Bordeaux. The new winemaker, John Clews, who packed in accountancy in London to study oenology at UCLA-Davis, is liberal with barrel samples: a tasting nightmare for anybody used only to the finished product. But we shock half the customers of Piatti's in Yountville by taking half a dozen bottles to dinner. Wines with lush Napa fruit and a bit of French restraint - like the Semillon-based Ariadne and velvety but powerful Cabernet Reserve.
Day 2, The Heart Of Napa:
A disparate collection of pick-up trucks and sheds. No signs. This is Caymus - refreshingly modest for Napa, which has a high quotient of fanciful "chateaux" among its 273 wineries. Chuck Wagner, the proprietor, takes me past the vegetable patch to meet his mom (83). "What're you doin'?" he asks her. "Hangin' out the laundry," she replies. "What're you doin'?" "We're just drinkin,' grins Chuck. "My," she exclaims, "that sounds like fun." And fun it is, because this self-taught winemaker, raised as a grower of prunes and walnuts as well as grapes, makes truly stunning, subtle Cabernets, mainly from bought-in grapes. The only problem is price - about £100 here for the Special Selection. (Mitchells or Direct Wine Shipments, Belfast). He winces. "Do I buy wines at that price myself? No, but I tasted my wine blind alongside a lot of other top Napa Cabernets including Opus One, and to me it was as good as any of them, so why not charge the same kind of money?" Further up the narrowing finger of Napa to Beringer, another big, coach-tour-friendly operation but one to which buildings from the 1880s and manicured gardens lend a polished charm. The winery launched by the German Beringer brothers kept going even through Prohibition, making wine for sacramental and "medicinal" purposes (670,000 prescriptions written in 1929). These days, cheap white Zinfandel accounts for 80 per cent of its business, but some serious wines make up the rest, culminating in the luxuriously rich and multi-layered Beringer Napa Valley Cabernet Sauvignon Private Reserve (Irish price about £55).
Back on the Silverado Trail, Joseph Phelps takes the prize for splendid wines in splendid surroundings. A Colorado construction engineer, Joe Phelps was bitten by the vinous bug while building several Napa wineries. His own is a theatrical redwood barn crowning a hill of vines. But Phelps has half a dozen vineyards dotted all over Napa's prime land, and a relentless replanting programme. Viognier and Syrah are interesting; Chardonnay and Cabernet superb.
Day 3, Far North To Mendocino:
A breath of fresh air. Warm, lavender-scented air. Imagine a herb and organic vegetable garden like Darina Allen's on a wine estate, where you can come to stroll around, sample the produce and stay the night in a pretty B & B. At the northern extremity of California wine country, Valley Oaks Ranch is the home of Fetzer, a huge company with a small company feel. Way up here, life seems laid-back - though it cannot have been so back in the 60s, for the 11 children of Barney Fetzer. Anxious that they shouldn't veg out in front of the TV, he bought a vineyard and set them to work. When the first wine was made by 16-year-old Jimmy in 1967, all the bottles exploded. Hard to contemplate in the vast, hi-tech Fetzer winery today. The best wines so far are the organic Bonterra range, inspired by the vegetable garden. Adventurous food-and-wine-matching activists, Fetzer's culinary team cooks up dishes to make the wines leap into life. Seared scallops with sauted apples and vanilla-scented sauce for the flavoursome Bonterra Chardonnay, for instance. Yum.
Day 4, Russian River Valley:
Narrow roads, lined by giant redwoods, snake the Russian River as it corkscrews from the centre of Sonoma County to the sea. Another microclimate, cooled by sea mists. More good Chardonnay and Pinot Noir. The Rochiolis are typical of the Italian immigrants who settled here early in the century to grow hops and grapes. "Back in the late 60s the farm advisers said this was a white wine region," explains Tom Rochioli. "But my father Joe said `we've gotta have some red'." A good thing, too. This two-man band - Joe farming, Tom wine-making - makes gloriously perfumed, seductive Pinot Noir: both the estate wine and the single vineyard West Block are a dream.
"One wrong turn and you'll be lost in the backwoods of Sebastopol for a week," I had been warned, leaving Rochioli for Marimar Torres. By some miracle, getting there was fine. But wrong turns could come at any moment with this spirited member of the Spanish wine dynasty who's known as the Catalan Firebrand. Marimar Torres has got where she is - mistress of a brand-new, quality-driven winery on an estate planted from scratch - by awesome determination. Her assertive wines are delicious with the lunch dishes she has chosen from two Marimar cookbooks - but if they hadn't been, would I have dared even whisper it? To end the day, a dart back north to Lytton Springs in warm Dry Creek Valley - famous for its old Zinfandel vines. Ridge Vineyards make some of the most celebrated, from vines planted up to a century ago, and as a bonus at the tasting counter there's also Monte Bello, Ridge's magnificent Cabernet-based blend from the main property at Santa Cruz (Irish price about £65). Worth the drive.
Day 5, Sonoma - Kinda Neat:
All week I've been hearing it. "Sonoma's real pretty." "Sonoma's kinda neat." Today, driving past small farms and country stores (Glen Ellen's included) to the cosy little town of Sonoma with its sleepy central plaza, I see what they mean. Compared to fancy Napa, a mere mountain ridge away, it's down-to-earth - more wild California poppies than cosseted roses.
Sebastiani, at the town's core since 1904 and now the fifth largest wine company in the US, still upholds family tradition by making Barbera, one of the fashionable Italian varietals that other Californian wineries merely flirt with. Sonoma Cabernet and Zinfandel make decent drinking, too (see below). But, as so often happens in huge organisations, the wines are swamped in a torrent of silver-tongued marketing spiel.
Not so up the hill at Ravenswood, a smaller, funkier winery with soft jazz in the tasting room and quiet passion about wine radiating from a friendly team. For over 20 years Joel Peterson has been making an amazing assortment of wines - a plethora of Zinfandels and Merlots, a few Cabernets and Chardonnays, a Petite Syrah, a Rhone blend, even a pair of Gewurztraminers - all brimming with personality. "He just enjoys the fun of it," says a colleague. It shows.
The trip verdict overall? Head-spinning hedonism. Hundreds of exquisite wines to discover, there or here - wines that are more consistent on the whole than their European rivals and more immediately enjoyable, with the warmth of the sun shining through. There is just one downside - as coldly depressing as that North Coast morning fog. Price.
Finding It All Back Home - White:
Fetzer Vineyards Echo Ridge Sauvignon Blanc, 1998 (widely available, usually £6.99). This simple quaffer, listed for affordability, shows a new side to Californian Sauvignon - light and lively. Alvaro Espinoza, winemaker at Carmen in Chile, helped out as style consultant.
Joseph Phelps Chardonnay, Los Carneros, 1997 (McCabes Merrion, Grapes of Mirth, Rathmines and a few other outlets, £18£19). From a Burgundyloving outfit, a beautifully smooth, harmonious wine that isn't OTT.
Marimar Torres Don Miguel Vineyard Chardonnay 1996/97 (Mitchells, Kildare St & Glasthule, Redmonds, Ranelagh, Deveneys group, McCabes, Merrion, Martha's Vineyard, Rathfarnham, Jus de Vine, Portmarnock, De Vine Wines, Castleknock, £20-£22). The citrussy 1997 is subtly powerful; the 1996 a much richer, more buttery wine. Both have real class.
Red:
Sebastiani Sonoma Cask Zinfandel, 1996 (Superquinn, Redmonds, Ranelagh, On the Grapevine, Dalkey, Egans Food Hall, Drogheda, Noble Rot, Navan, and some other outlets, usually about £10.49). Full credit to the Sonoma giant for delivering a gutsy, distinctive Zin from old vines that you don't need another Gold Rush to buy. (See Bottle of the Week.)
Bonterra Vineyards Cabernet Sauvignon, North Coast, 1996 (Molloys Liquor Stores, Sweeneys, Dorset St & Fairview, Raheny Wine Cellar, Vintry, Rathgar, Redmonds, Ranelagh, Lord Mayor's, Swords, Lawlors, Carlow, Wine Centre, Kilkenny, and some other outlets, usually about £11.99). I've praised this rich, beguiling Cabernet before and may again: the organic Bonterra wines mark an exciting step up for Fetzer.
Ravenswood Zinfandel, Sonoma County, 1997 (this vintage coming soon to Mitchells, Kildare St & Glasthule, and some other outlets, about £15). The Vintner's Blend Zin is Ravenswood's bestseller, but for an extra few pounds this lusciously concentrated number has a lot more oomph. A fair price.
Robert Mondavi Napa Valley Cabernet Sauvignon 1995 (McCabes, Merrion, Redmonds, Ranelagh, Thomas's, Foxrock, and some other outlets, about £25). While the humbler Mondavi wines can be disappointing for the money, at this level they emerge triumphant, with terrific body and flavour. The Napa Valley Merlot is glorious, too.
Rochioli Estate Pinot Noir, Russian River Valley, 1997 (this vintage available from mid-July, Raheny Wine Cellar or through James Nicholson, about £25). If you've the patience to wait and the cash to spare, make this your Bottle of the Week. Pinot Noir is my Grape of the Trip - and Rochioli a seriously talented exponent.