Italy's barbera vies with the sangiovese of Chianti for the dubious title of Italy's most widely planted red grape. The 'dubious' is because the fact that a grape variety is prolific does not mean that it makes the greatest, or even the most popular, wines. As in the case of the carignan grape of the Languedoc, widespread planting can have more to do with resistance to disease, adaptability to the environment, and the capacity to produce copious fruit than the quality of the grape per se.

Barbera's origins are obscure, but it is generally accepted as a native of Italy, where it performs best in the hills of the north-west around Asti and Alba. It is low in tannin and potentially very fruity, but it can also be extremely tart and prone to bad-egg sulphurous odours. Until recently, it was regarded primarily as a workaday grape, making wines in varying styles - dry, medium and sweet - some for drinking and some for blending.

'Low to medium quality, not fashionable,' said Jancis Robinson in Wines, Grapes and Vines in 1986. 'One wonders whether barbera would occupy half the space it does today were it not for the fact that a high-acid grape makes useful blending material.'

It was a blending material of a different kind - methanol - that in 1986 led to barbera's implication in Italy's most notorious wine scandal. Surprisingly, instead of burying the variety, the disgrace served to bring changes for the better.

Piedmont has been the focus of the revival of interest in the barbera. The Alpine foothill region, which itself has undergone a dramatic change in quality in 10 years, has spent most of its energy adding new lustre to barolo and barbaresco, the king and queen of Italian reds, both made from the nebbiolo grape.

Angelo Gaja, pioneer of the modern style in Piedmont, used a barbera from a three-hectare vineyard called Vignarey. He was one of the first to recognise that well balanced and judiciously oak-aged barbera would appeal to palates beyond Italy. 'Barbera is finally showing what it can do if given a chance,' he says. 'Among the 250 million bottles produced in Piedmont, there's a wide gap between the pallid, high-volume, acidic barbera and the deep-hued, low-yielding barbera. It should be possible to produce 25 to 30 million of the latter.'

Single-vineyard bottlings and temperature control have contributed to improvements in wines made from barbera. The use of oak barriques tends to produce a more complex style, as does blending with nebbiolo. Above all, very low yields have contributed to the transformation of barbera into a variety that the American critic Burton Anderson once said 'seems almost on the verge of becoming chic'.

Paul Merritt and Michael Garner, in their book on barolo, put it higher: 'Its downmarket image is a travesty - in the hands of the right winemaker, barbera is a budding superstar.' They describe it as giving 'deep, dark, purple-coloured wine full of bramble and cherry fruit and often characterised by spicy and aromatic tones reminiscent of seasoned leather'. Although barbera does not always quite live up to this billing, a good one is at least, with its naturally crisp acidity, an ideal foil for Italian food.

'For good barbera producers read good barolo and barbaresco producers and you won't go far wrong,' says Mr Merritt. Mr Gaja's Vignarey is good but expensive. Elio Altare makes an international-style barbera from stumpy, 45- year-old vines in his Vina Larigi vineyard. Aldo Conterno, a master of barolo, also makes outstanding barbera: his Barbera Conca Tre Pile is one of Italy's best, with the right balance of rich, concentrated fruit and spice from barrel-ageing.

The 'modern' names to look out for include Josetta Saffirio, Andrea Oberto, Roberto Voerzio, Conterno Fantino, Paulo Scavino and Domenico Clerico.

The more traditional merchant firm of Prunotto does not use barriques, but ages its barbera, Puan Romualdo, in large new oak casks to emphasise the fruit character. 'We're not trying to make modern wine, but to increase the personality of our barbera,' says Tino Colla, Prunotto's winemaker.

The ascetic ex-schoolmaster Aldo Vajra makes wines to match his monkish looks, preferring to steer clear of new oak altogether: his wines emphasise colour, vibrancy and intensity of fruit. His powerful, blackberry, single-vineyard barbera, Bricco delle Viole, is not for the faint-hearted.

Given the relatively small quantities produced and the demand for the increasingly fashionable names, barbera at the single-vineyard estate level no longer comes cheap. At the level of co-operatives and bigger negociants, quality is more hit-and-miss. But when you find it, good barbera at a fiver or less can make an excellent introduction to the wines of Piedmont. Anyone who has successfully negotiated the foothills of barbera should then be equipped for an assault on the twin peaks of barolo and barbaresco.

1991 Barbera d'Mba, Conca Tre Pile, Aldo Conterno, pounds 10.25, Winecellars, 153-155 Wandsworth Road, London SW15 (081-871 2668). Elegant thoroughbred with cedary scents and rich, concentrated fruit cut by crisp acidity.

1990 Vigna Clara, Barbera d'Alba, Viberti Luigi, pounds 9.50, Bibendum, 113 Regent's Park Road, London NW1 (071-722 5577). Smoky, oaked, peppery, with ripe-fruit sweetness.

1991 Sara, Barbera d'Alba, Josetta Saffirio, pounds 7.85, Bibendum. A ripe core of concentrated sweetness tempered by fresh acidity and stylish oak spiciness.

1990 Prunotto Pian Romualdo Barbera d'Alba, pounds 9.65, Lay & Wheeler, Colchester (0206 764446). Sweet raspberry and cherry fruitiness with lively bite makes this a fine traditional barbera.

1991 Barbera d'Alba, Giada, Andrea Oberto, pounds 12.95, Lea & Sandeman, 301 Fulham Road, London SW10 (071-376 4767). Expensive, fine, aromatic modern style with a hint of vanilla oakiness.

1991 Ceppi Storici, Barbera d'Asti, pounds 4.95, Winecellars. More juicy, spiced oak red at this price could give barbera a good name.

1991 Barbera Mombaruzzo, pounds 3.49, Oddbins. Robustly fruity affordable one to quaff with pasta.