No grape has known such a dramatic upgrade in its fortunes and image in the last 20 years than Barbera in Piemonte, north-west Italy.

This grape was once regarded as rather ordinary, partly because it was so widely planted, the most common Piemontese grape in fact. (A similar fate had befallen Shiraz in Australia, Zinfandel in California and Malbec in Argentina – all now considerably elevated in reputation.) Light, tart Barbera was the everyday drinking wine on Piemontese tables, something to wash down the wondrous local cuisine and its succession of courses, paving the way on special occasions for a bottle of a serious red wine made from Nebbiolo.

The man who first put Barbera on a pedestal, or at least demonstrated that it was capable of making serious wine rather than local mouthwash, was the late Giacomo Bologna of the Braida estate whose Bricco dell'Uccellone was the first internationally marketed Barbera. The wine, which has since been followed by hundreds of increasingly expensive imitators, owed its distinction to two factors, much lower-than-usual yields and ageing in French oak barriques.

Like the much softer local grape Dolcetto, in Piemonte Barbera has traditionally been planted on sites too cool or poorly exposed to bring the late-ripening Nebbiolo to full ripeness. (Dolcetto ripens early relative to Barbera, but Nebbiolo typically needs a further two weeks on the vine after Barbera is picked.) It is an extremely vigorous vine and even the DOC laws sanction yields as high as 70 hl/ha so the temptation has been to allow this prolific vine to over-produce. Barbera's natural excess of acidity and shortage of tannin are accentuated at high yields. But if Barbera is grown on sites specifically suited to it and pruned carefully, more concentrated wines are the result.

They still have rather a shortage of tannin however, but this can be counterbalanced by oaking and the additional framework of oak tannins. Which still leaves that high acidity. Many modern winemakers quietly deacidify Barbera (by adding harmless calcium carbonate for example) to give it extra appeal in an age when wine consumers are – wrongly in my view – taught to be shy of acidity. Fermentations tend to be shorter than those of Nebbiolo but longer than for Dolcetto.

Barbera is not intrinsically the most flavourful grape in the viticultural universe – a vague blackberry quality plus tartness is about as close as one can come to the essential flavour of Barbera. The army of oaked Barberas which has invaded the Piemontese wine scene (filling the price gap between basic Barbera and Dolcetto and the wines of Barolo and Barbaresco) have tended to rely quite heavily on the oak itself for aroma. Time has shown that as these Barberas age, the oak increasingly dominates, as what little fruit the Barbera itself contributed fades. Few oaked Barberas are better at 10 years than they are at five. There is therefore a strong argument for blending Barbera with other, more flavourful and tannic grapes. Some have tried Cabernet Sauvignon but Cabernet has too much personality to make a meek blending ingredient. Others report more success with the perfumed local Freisa, while others bottle blends of Barbera and Nebbiolo grapes. Indeed Barbera was long used in Piemonte to add colour to wines the consumer thought were made exclusively of Nebbiolo.

The Monferrato zone lays claim to being Barbera's birthplace, and records of it growing there exist as far back as the 13th century. But the hills around Alba and Monforte d'Alba have proved they are capable of growing some particularly fine Barbera, as are parts of the Asti province.

Barbera is an easy vine to grow, and in the south of Italy is treasured for its usefully high level of acidity, so is it is widely planted not just in Piemonte. It is by far the most common grape in Lombardy around Milan, particularly in Oltrepò Pavese where it comes in every imaginable shade of crimson and degree of fizziness. It is also the staple red grape of the hills above Piacenza, the Colli Piacentini. Here its softer blending partner tends to be the grape known locally as Croatina. Often it makes the most basic vino da tavola but one of its more famous incarnations is Gutturnio, in which it is blended with Croatina.

All over central Italy Barbera is used to add ballast to local grapes in blends, but in the south it is positively valued for its naturally high acidity. Sardinian growers identify their own strain of Barbera as Barbera Sarda. It is rarely featured on glorious labels outside Piemonte however. Only in this illustrious region has it so far established its own fame, but if price is anything to go by, that fame is prodigious – so long as oak is involved.

The only wine region outside Italy but within Europe to make much fuss of Barbera is just over the Italian border in the Primorski coastal region of Slovenia where the wines tend to have their own prickle of carbon dioxide. Outside Europe however there has been a fascination with all things Italian, from which Barbera has inevitably benefited. California has quite substantial areas planted to it, originally in the hot Central Valley where it was planted by Italian immigrants originally. Most of the focus of the Cal-Ital phase was focused on Sangiovese with its trendy Tuscan connotations but Barbera was the better-established vine and a few successful bottlings have been known.

In South America Italian immigrants planted even more sizeable tracts of Barbera in Argentina's dominant wine provinces, Mendoza and San Juan at the foot of the Andes in the far west of the country. Producers as well established as Norton have been bottling varietal Argentine Barbera for decades. The wine shares the high acidity of Piemontese versions but benefits from the addition of all that South American sunshine which fills out the palate

In Australia there has also been a recent flirtation with all things Italian and Barbera has been responsible for one or two interesting wines – particularly in the state of Victoria. Charles Back of Fairview is the South African pioneer of Barbera (and much else) and in this warm climate values its ability to hang on to both acid and fruit even in a hot vintage.

Some top Barberas include Giacomo Bologna's Bricco dell'Uccellone, Elio Grasso's Vigna Martina, Coppo's Pomorosso, Bava's Stradivario, Vietti's Scarrone Vigna Vecchia and Norton's Argentine version.