Of all the wine regions in the world, California is the most fun to visit. The climate is benign. The people could not be more welcoming (in stark contrast to Bordeaux and Burgundy, the wineries of Northern California seem to operate for rather than despite tourists). The food is fantastic; you can eat superbly, and be served wine knowledgeably (by the glass or bottle), in hundreds of sensibly priced restaurants. In most of California's wine regions the gentle, golden landscape is well protected against the construction industry's baser instincts. Life is easy; man has devised ways of overcoming all natural discomforts. To a California wine producer, lifestyle can be what it is all about.

The California wine business is easily misunderstood from the outside, however. It seems blindingly obvious in the most famous wine regions of Napa and Sonoma that winery proprietors here live a charmed life, enjoying a standard of living unknown among wine producers since the Golden Age of the Médoc estates in Bordeaux. They live in lovingly restored Victorian mansions or villas specially commissioned from famous architects. The most privileged of them may have not just swimming pools and poolhouses, but their own stables, art galleries and concert halls. They play croquet at the country club and jazz at the regular charity auctions.

This glossy façade is often coupled with the fact that so few California wine bargains are seen outside the US, and interpreted as gross overcharging or misplaced priorities in the California world of wine – especially as virtually every other wine-producing nation seems desperate to export at whatever price we'll pay. What such criticisms overlook, however, is the size of the American population. California does not need to export in the way that Australia, Chile and the classic wine producers of Europe do – especially now that wine drinking has become a mainstream American pursuit.

It is a great shame for us non Americans that most of the California wine exported is in the form of the likes of mass-market brands such as Blossom Hill and Gallo's most basic bottlings. But because Californians have not carved out a solid base of non-American consumers introduced via less expensive bottles, many of the world's wine drinkers are unaware of the sheer exciting glamour of the state's finest wines, which, thanks to local demand, can seem overpriced. Indeed, even those of us who are already convinced of California's achievements can find it difficult to keep up with the latest developments unless we live in the state itself – so small are some of the quantities involved, and so fast-changing the roster of winery and wine-making names.

This lack of permanence is one of California wine's distinguishing marks. Even if few New World wine regions experienced such a dramatic boom as California did in the 1880s (when wine from what was by then established as America's 'wine state' was admired around the world), almost all of them have at least experienced fairly constant evolution. California's wine history is a series of jerky stops and starts, with phylloxera pulling the plug on the 19th century performance and total national Prohibition stopping play altogether between 1918 and 1933.

It was not until the late 1960s that a serious, ambitious, premium California wine industry began to emerge (the construction of the Robert Mondavi winery in Oakville, Napa, still one of the most recognisable landmarks of California wine, is generally agreed to mark the start of this new era). Throughout the 1970s and 1980s, California wine country, particularly the Napa Valley and to a lesser extent Sonoma, were invaded by those who had made a fortune in a more conventional business but were determined to exchange it for the good life. Some of northern California's finest reds were made at the start of this era – as witness their rousing performance in the famous Judgement of Paris tasting in 1976 when California wine 'beat' the best of France.

With one or two notable exceptions, the California wine industry is the friendliest, least competitive, most open in the world. Which means that when a new idea or scheme appeals to one of these new wine producers, it tends to spread like wildfire throughout the industry. Trends have, furthermore, been accentuated by a very concentrated, critical national wine press and conservative, almost obstructive, wholesaling and retailing systems. Points awarded by either the Wine Spectator magazine or the critic Robert Parker have been used so widely and unquestioningly both to buy and sell wine that there are now consultancies offering a template of the sort of wines that attract high scores and ways and means of achieving them. The critics tend to award high points, for example, to Cabernets and Zinfandels that are very deep-coloured, very ripe, with high alcohol and perceptible but ripe tannins (the sort of wines that stand out in a big comparative tasting – though not necessarily the ones that are most rewarding to drink with food).

Because of this, winemakers all over California have been seeking riper and riper grapes, and growers have been pushed to extend the ‘hang time’ of grapes on the vine. It is by no means unknown for such grapes to be picked with a potential alcohol content of 17% or more. Some of them have been bottled and labelled as is. Others are routinely diluted or have their alcohol reduced by other means to bring them back to a more digestible level of alcohol. Similarly, a few high-profile winemakers enjoyed enormous acclaim for their equally enormous Chardonnays, laden with sweetness, alcohol, extract and oak. You can imagine the effect of this on the state’s Chardonnays, of which there are thousands, remarkably difficult to tell apart.

The result of this is that a wine-producing development, which in any other part of the world might be a just-perceptible eddy, can in California easily become a tidal wave. One obvious brake on progress in California, although this began to change in the 1990s, has been the emphasis on winemaker at the expense of vine-grower. As in most New World regions, the functions of grape growing and winemaking are often quite distinct, with cash-conscious farmers supplying more urbane characters, who tend to have cleaner hands and lab experience, with the necessary raw material. The heat of a California summer has also helped to keep the state’s vineyards the domain of the Mexican workforce rather than its new generation of wine producers. At long last, however, the California wine industry acknowledges that the best winemakers are those who know their product from the roots up.

The good news is that California growers have been encouraged to widen the range of good quality grape varieties grown. (There was always a soft underbelly of workhorse varieties such as French Colombard and Chenin Blanc for cheap whites and Carignane (sic) and undervalued Grenache for light reds.) The general wine-drinking public – and possibly winemakers – at long last tired of oceans of bland Chardonnay and Sauvignon Blanc (considerably fatter and less herbaceous in California than in the cooler climes of the Loire or New Zealand) has increasingly been allowed to flourish. Throughout the 1990s Rhône varieties both red and white became increasingly fashionable. This led to widespread planting of Syrah, a re-evaluation of Grenache and the grape Italian immigrants called Mataro (which turned out to be trendy Mourvèdre), Viognier (which reaches incredible alcohol levels here), Roussanne and Marsanne.

And then, in the early 21st century, came the movie Sideways, dedicated to the glories of Pinot Noir. This made the red burgundy grape literally an overnight sensation. The variety had already emerged as rather a star in some of the state’s cooler corners – in some cases having initially been planted to supply the sparkling wine industry which took off with a whizz in the 1980s, attracting enormous investment from Champagne and Catalonia, but had rather fizzled out by the end of the century. But demand for sweetish reds labelled Pinot Noir soared to such an extent that the variety is now grown all over the state, even if especially in Central Coast regions in southern California.

Although midsummer afternoon temperatures in most California vineyards are blistering, in the best sites they are mitigated by a unique climatological phenomenon which delays ripening so that interesting flavours and structure develop, and is the main reason why California can produce serious wine at all. The Central Valley, the baking hot, flat sprawl of vineyards between Sacramento in the north and Bakersfield in the south, is indirectly responsible for this phenomenon, and for an amazing three quarters of all the wine produced in the state (as well as the world's biggest supply of raisins). Yields here are so high that a substantial acreage of the colouring grape Rubired is planted to tint pale red wines.

The unremittingly high temperatures in the Central Valley encourage the cold wall of fog that hangs over the Pacific for much of the summer to be sucked into the narrower valleys between the coast and the Central Valley, depending on how much land mass is in the way. The marine expanse of the San Pablo Bay north of San Francisco in particular encourages morning fog to cool down the Carneros region on its northern rim, and the southern ends of the Napa Valley and Sonoma's wine districts too. In fact in Northern California it is an almost invariable rule that the further north you travel, the warmer it gets.

If Napa and Sonoma are the Bordeaux and Burgundy of California in terms of attracting all the attention and high prices, the Central Valley is its Languedoc-Roussillon which really does the work – except that while the Languedoc is now fashionable in certain quarters, there seems to be no such danger for the Central Valley.

The far northern end of the Valley around the state capital is, strictly speaking, the Sacramento Valley where Lodi and Clarksburg not far from the Sacramento Delta can produce some much more distinctive red and white wines respectively than further south. But most of the vineyards are well south of here in the San Joaquin Valley, with a third of the annual crush being supplied by the vineyards of Madera and, to a lesser extent, Fresno counties. High-yielding French Colombard (the local name for Colombard) and Chenin Blanc produce vast quantities of medium dry white for jug wine but Zinfandel is an important red wine grape and Quady has shown that there is potential for dessert wine and port and Madeira styles, next time they swing into fashion.

In the state's wine showcase the Napa Valley the land round the Trefethen Family winery in the far south is quite significantly cooler than in Calistoga at the northern end of the valley. 'The Valley', as it is known by its residents, is fiercely protected by ordinances designed to keep its agricultural base and even today produces only a tiny fraction of all California wine. As recently as the early 1970s, this narrow 20-mile stretch of valley floor was planted with crops as unglamorous as walnut and plum trees. Today, Highway 29, which bisects the valley, is lined with variously spruce, folksy, kitsch and slick wineries, each apparently frantic to attract any visitor to its tasting room and winery tour. The middle reaches of the valley floor, around Oakville, Rutherford and Stag's Leap, have established an entirely justified reputation for their intensely coloured and flavoured Cabernet Sauvignon which regularly exhibits a layer of richness most Bordeaux wine producers only dream of. Many of the most consistent vineyards lie at the foot of the low mountains which define the valley floor. Hillside sites, with their excellent drainage and low fertility, might well prove even more exciting sources of wine quality but there are tight controls on land use in such developed wine regions as Napa Valley and Sonoma. Since so many wineries buy in grapes from a wide variety of sources, there is often little correlation between winery location and the style of wine it produces. The Napa Valley has, however, proved a source of great Cabernet Sauvignon, and some very good Chardonnay in Carneros in the far, cool south. Some of its most famous Cabernets are made in such tiny quantities that they have achieved cult status, being eked out by the single bottle sometimes only to those lucky enough to be on the mailing list for such names as Screaming Eagle, Harlan/Bond Estate, Araujo, Grace Family, Colgin and Bryant Family. These wines regularly fetch completely crazy prices at the charity auctions which are a feature of the American way of wine.

Such has been the reliance of winemakers on new oak for fermenting white wines and maturing wines of both colours that the Valley houses several highly successful cooperages. There is such a concentration of ambition and high achievement in the Valley that it seems invidious to name names, but other labels with an established track record for top quality include Caymus Special Selection, Chateau Montelena, Cuvaison, Dalla Valle, Diamond Mountain, Dunn, Heitz Martha’s Vineyard, Hess Collection, Robert Mondavi Reserve, Newton, Rubicon Estate Winery, Joseph Phelps’, Stag’s Leap Wine Cellars, Shafer Vineyards, Silver Oak, Stony Hill, and two joint ventures with Bordeaux luminaries Dominus/Napanook and the luxuriously priced Opus One.

For years Sonoma could not help nursing a grudge about the publicity attracted by Napa Valley, its neighbour just over the Mayacamas Mountains to the east, but the stunning quality of so many of its wines, exhibiting the sort of district/varietal patterns that comfort wine classicists, has given Sonoma new pride and status. The easiest generalisation was that Napa made the Cabernet and Sonoma the Chardonnay but there is much more to the varied wine districts of Sonoma than this. Alexander Valley around Geyserville in the north seems to be able to produce a well-balanced example of virtually every varietal. Chalk Hill to the immediate south makes fine Chardonnay while Dry Creek Valley to the west enjoys a well-deserved reputation for Zinfandel from ancient vines planted by Italian immigrants a century ago and aromatic Sauvignon Blanc. Dry Creek Vineyard is the Sauvignon Blanc specialist while Lytton Springs, Nalle, Ravenswood and several Ridge bottlings have established Dry Creek's reputation for Zinfandel.

Thanks to a gap in the coastal range, the Russian River Valley south of this is even foggier and can therefore produce wonderful examples from more delicate varieties such as Chardonnay and now especially Pinot Noir (as Williams Selyem and J. Rochioli were some of the first to prove). Producers such as Ferrari-Carano, De Loach, Kistler, Matanzas Creek, Marcassin, Peter Michael and Sonoma-Cutrer show just what can be done with Sonoma Chardonnay – depth as well as gloss. Top-quality sparkling wine is also made here by Iron Horse and J. Sonoma has also been chosen by Gallo as the focus of its range of finer Estate wines. The even cooler and expansive Sonoma Coast region is yielding some of California's most interesting Pinot Noir and Chardonnay from producers such as Littorai. A local campaign is underway for more specific subregions to be recognised: Fort Ross-Seaview AVA was the first.

South of Sonoma and Napa and straddling both counties is Carneros, whose reliable fog quotient keeps it cool enough to be the most important source of sparkling wine grapes in the state (even if most of them are trucked out to be vinified further north). Taittinger have built a replica of a champagne manor house in Domaine Carneros while the Spanish colossi of sparkling wine have established Codorniu and Gloria Ferrer. Saintsbury and Acacia make extremely thoroughbred still Pinot Noir and Chardonnay and Fred Cline is busy making a little enclave of Rhône varieties at the south-western end of Carneros.

California's 'Rhone Rangers' scoured the state in the early 1990s looking for low-yielding old plantings of Mourvèdre and Grenache, spurned for many years but have now been joined by enthusiastic planters of these varieties in warmer parts of the Central Coast. Cline's grandfather's plantings in Contra Costa country just east of San Francisco were an important source while newer plantings of Syrah, Viognier, Roussanne and Marsanne matured.

To the north of Napa and Sonoma are Mendocino and Lake counties, rather hotter and much less sophisticated. Fetzer/Bonterra – now owned by Chilean wine company Concha y Toro – specialise in organically farmed vineyards – and indeed California's extremely low rainfall means that much of the state could be farmed without recourse to chemical sprays. Even Gallo, the California wine giant based at the world's largest winery in Modesto in the Central Valley, deliberately increased their 'organic' acreage (at the same time as zooming upmarket, notably on their Sonoma estate). Roederer Estate and Scharffenberger make some fine sparkling wines in the cooler reaches of Anderson Valley, which fall in Mendocino county, while Navarro make some of California's most consistent Riesling and Gewurztraminer.

In the Sierra Foothills, the old gold mining counties El Dorado, Amador and Calaveras still have thick-stemmed vines, mainly Zinfandel, which date from the 19th century. Since being rediscovered, these far eastern vineyards have produced Zinfandel in all forms, from porty to pink (‘White’) as well as a wider range of varietals than is common in Napa and Sonoma.

High on a ridge above Silicon Valley south of San Francisco in the Santa Cruz Mountains is Ridge Vineyards, established as a weekend hobby as long ago as 1962 and one of the state's standard bearers for Zinfandel and Cabernet quality for decades. The California habit of trucking in fruit reaches the heights, literally, of apparent absurdity here. But the wines are terrific.

A little further south is Monterey county, where valley floor vineyards have struggled to eliminate grassy and vegetal flavours from their wines but there are exciting, idiosyncratic outposts in the mountains to the east, such as Chalone and, on a limestone outcrop technically in San Benito county not Monterey, Calera. Both of these make some exciting Pinot Noir and Chalone's Chardonnays and Pinot Blanc are notable. Santa Lucia Highlands have shown great promise for Pinot Noir .

Perhaps the most exciting developments for California wine have taken place south of here where plantings have been so enthusiastic that the casual visitor driving from Monterey to Santa Barbara might be tempted to think this is now one long vineyard. While anything planted north of San Francisco is called North Coast, this is the vast region known as Central Coast. Right through San Luis Obispo and Santa Barbara counties are areas which, thanks to incursions of the fog layer, can extend the grape-growing season to produce grapes with interesting flavours and, often, a vaguely Burgundian nuance. This is particularly true in the Santa Maria Valley north west of Santa Barbara where producers such as Au Bon Climat show just what can be done with the produce of the extensive Bien Nacido vineyard. In the Arroyo Grande a little bit north, Talley and Laetitia show just how well the Burgundian varieties Pinot and Chardonnay can perform here too, while Alban even further north in Edna Valley is one of California’s finest producers of Rhôneish wines, red and white. Santa Ynez Valley is the largest wine district in this stretch, with its far western end, known as Sta. Rita Hills, a hotbed for fine Pinot Noir activity.

Most of these producers tend to cherry-pick the many different grape varieties that seem to thrive in various corners of the extensive Central Coast region, wherever they may be based. The Central Coast has also become an important source of grapes for some of the most famous names of the Napa Valley, Robert Mondavi and Beringer in particular. But the wine bug is so virulent throughout California that there are even ambitious wine producers crazy enough to be planting vines within some of Los Angeles’ most sought-after arondissements.

See California Wine for more information on this region. 

In a nutshell

Some very fine wine indeed but relatively few bargains.