In a nutshell: The home of port, madeira and a host of increasingly modern, often bargain, table wines.

Grapes: Rich variety of local specialities.

Portugal's advantage in wine terms – its isolation, which has kept its inheritance of indigenous vine varieties intact and virtually unaffected by Chardonnay- and Cabernet-mania – has also been its disadvantage. The Portuguese have had this strange habit of making wines to suit the palates of other Portuguese rather than making the sort of fruity, juicy-yet-structured wines that appeal to the majority of the world's wine consumers. The wines that have traditionally been most respected within Portugal are incredibly tough reds that have typically spent rather too long in storage before being bottled and some slightly tired whites whose unfamiliar flavours may strike some outsiders as slightly rank.

In fact Portugal has some first-class raw materials and is increasingly demonstrating the will and skill with which to transform them into exportable wines. There seems to me to be little correlation, however, between the country's denominated regions (DOCs) and inherent wine quality. Dão is one of the traditionally most respected wine regions, for example, but I have found infinitely more pleasure in bottles from much more obscure corners of this essentially Atlantic-influenced country (where vines are grown almost everywhere).

Rainfall varies enormously according to proximity to the coast. The Vinho Verde region in the far north west, famous for light, dry whites, for example, is one of the wine world's wettest, while the Douro Valley to its immediate south east is one of the driest during the crucial growing season. This extraordinarily arid, harsh valley is responsible for Portugal's second greatest gift to the wine world, port, the sweetest, strongest, darkest wine known to man and his cranium. Its most significant contribution of course is cork, of which it is by far the world's most important source.

Wine production has been largely in the grip of co-operatives, which have only slowly been rejuvenating their ideas and techniques. The picture is further confused by the fact that some of the DOCs - Carcavelos for example - reflect Portugal's rich wine exporting history more than modern reality.

The main wine regions follow, roughly from north west to south east.

Vinho Verde

In a nutshell: Crisp light whites, thin reds.

Main grapes: Loureiro, Azal Branco, Arinto, Trajadura, Alvarinho (white).

The verde or 'green' in Vinho Verde (pronounced something like 'Vino verge') refers not to the colour of the wine but to its youth. The red and white Vinho Verde wines produced in this rainwashed region just south of the Minho river, which forms the border with Spain and gives its name to Minho Viinho Regional, are all designed to be drunk when still young and fresh. High acidity and more than a trace of post-fermentation fizz is their hallmark. The more concentrated examples, produced by Quinta do Ameal, for example, bear a strong resemblance to the Rías Baixas wines made just over the river in Spain's Galicia - indeed the same aristocratic white grape variety, here spelt Alvarinho, is the most admired in the Minho region. Some of the more commercial bottlings are deliberately sweetened and slightly carbonated but the likes of Palacio de Brejoeira bottle a wine that a local would recognise. (The locals drink twice as much red as white but hardly any red is exported, with good reason.)

Some favourite producers: Quinta do Ameal, Quinta de Azevedo, Casa de Cello, Covelha, Quinta do Foz de Arouce, Quinta de Soalheiro.

Douro

In a nutshell: Concentrated, dark reds and complex dry whites.

Main grapes: Tinta Roriz, Touriga Nacional, Touriga Franca, Tinta Barroca and other port varieties (red); Viosinho, Gouveio, Rabigato, Códega and other port varieties (white).

The dramatic Douro Valley, for long dedicated almost entirely to port production, is now also a significant producer of robust, characterful red table wines with some of the tannins which distinguish vintage port. To some port producers, such Douro DOC table wines are heresy but to quality-conscious wine drinkers they are intriguingly satisfying, with a concentration of flavour many winemakers elsewhere would kill for. Port producer Ferreira produced the prototype, Barca-Velha, and it still commands very high prices, but an exciting range of less expensive dense crimson table wines is now available from the likes of Chryseia, Quinta do Cotto Grande Escolha, Quinta do Crasto, Quinta de la Rosa, Niepoort, Quinta do Passadouro, Ramos Pinto (Duas Quintas), Quinta de Roriz, Sogrape, Quinta do Vallado, Wine and Soul (Pintas). Highly recommended.

Dão

In a nutshell: Emerging from a time warp.

Main grapes: Tinta Roriz, Touriga Nacional, Alfrocheiro (red); Encruzado, Bical (white).

This large red and white wine region south of the Douro Valley was for long well and truly strangled by old-fashioned winemaking methods, particularly long maceration with bitter stalks and unwisely prolonged ageing before bottling so that the wines tasted hard rather than fruity. As recently as the end of the 1980s there was even a ridiculous statute which required all grapes to be handed over to co-operative wineries. The abolition of this monopoly and more modern winemaking have resulted in wines that are slowly becoming juicier and friendlier. The finest port grape, Touriga Nacional, is a significant ingredient in many ambitious modern red Dãos while Tempranillo, known as Tinta Roriz in most of Portugal, is also grown – although a host of other, less inspired varieties are allowed. White Dão has tended to be an even more anachronistic product, even if the Encruzado grape used in most blends can be quite crisp and fragrant.

Some favourite producers: Quinta dos Carvalhais, Quinta da Pellada and Quinta de Sães, Quinta dos Roques and Quinta das Maias, Quinta da Vegia.

Bairrada

In a nutshell: Improving but still potentially tough reds.

Main grapes: Baga (red); Bical, Maria Gomes (white).

Unusually for a Portuguese wine zone, this mixed farming region between Dão and the coast is dominated by a single grape, the small, thick-skinned Baga, which would result in relatively tannic wines even if all Bairrada wineries were equipped with destemmers. As it is, many of the all-important co-operatives still make tougher wines than necessary, although it is (just) thinkable that one day the concentrated reds of Bairrada might be as popular outside Portugal as they were in early 17th century London. Luis Pato is the leading maker of fine wine in the Barirada zone – whites and reds, still and sparkling -  but now bottles them as Beiras Vinho Regional (see below) because he disapproves of the current Bairrada rules which now allow the addition of some non-traditional grape varieties. More modern vinification equipment, as at Sogrape’s huge facility, are another sign that the region is in the process of revitalisation. Bical can yield some interesting dry whites and sparkling wines here.

The famous Bussaco Palace Hotel on the edge of Bairrada bottles its own blends of wines bought in both Bairrada and Dão, which are renowned as some of Portugal's best, but perhaps the region's most famous wine is the blended brand Mateus Rosé, which is produced at a giant winery within Bairrada. Mateus' mid 20th century success supposedly owed much to the fact that it was neither sweet nor dry, white nor red, still nor sparkling – though it has become drier in recent years. The Guedes family who developed Mateus have sensibly been branching out in to more distinctive wines under brand names such as Callabriga in Alentejo, Quinta da Azevedo in Vinho Verde and Quinta dos Carvalhais in Dão. With any luck, these will help to introduce wine drinkers all over the world to some of the flavours and styles Portugal has to offer.

Beiras, an increasingly important Vinho Regional that covers not only Dão and Barraida but also the lesser known DOCs of Beira Interior, Lafões and Távora-Varosa, is favoured by innovative and producers such as Filipa Pato, who makes both refreshing and concentrated whites from local varieties.

Some favourite producers: Quinta da Baixo, Dão Sul,Filipa Pato, Luis Pato, Casa da Saima

Colares

In a nutshell: An endangered species.

Main grapes: Ramisco (red); Malvasia (white).

This tiny DOC is more famous for its exceptional situation, a narrow strip of sand on the windy Atlantic coast not far from Lisbon, than for the quality of its wines. Since phylloxera cannot live in sand, the Ramisco vine responsible for red Colares (yet another tannic, tart Portuguese red) is possibly the only vine variety never to have been grafted on to phylloxera-resistant American vine roots. Here the modern wine drinker's interest in Colares may end. Some full-bodied white Colares is made from Malvasia grapes.

Bucelas

In a nutshell: Crisp dry whites.

Main grapes: Arinto (white).

Bucelas or Bucellas is a name often found on 19th-century decanter and bin labels in Britain, showing just how popular this 'Portuguese hock' was then. The wine is a potentially scented dry white based on Arinto grapes. It is made in relatively small quantity but some newish producers are trying hard, perhaps encouraged by the proximity of the capital Lisbon, and its thirsty populace.

Ribatejo

In a nutshell: Smaller than it used to be.

Main grapes: Castelão, Tricadeira (red); Fernão Pires

This large fruit- and vegetable-growing region upstream of Lisbon, whose name means the banks of the river Tagus, is an important source of basic blending wine (together with the Estremadura region between it and the Atlantic). You may see Ribatejo or Vinho Regional Ribatejano on the label. Much of the wine produced here is relatively light, but that can be a blessing relative to some of Portugal's more austere wine styles. Co-operatives rule the roost, but sometimes benevolently.

Setubal and Palmela

In a nutshell: Fortified sweet wines and exportable reds and dry whites.

Main grapes: Castelão (red); Moscatel (white).

The Setúbal (pronounced 'Shtooble') peninsula south of Lisbon is home to the two overlapping DOCs Setúbal and Palmela. The former produces a sweet, fortified wine (sometimes labelled Muscatel de Setúbal if it contains more than 85% Muscat). It is a noble, historic, copper-coloured wine to which grape spirit is added during fermentation so that it tastes like a cross between a southern French Muscat de Beaumes-de-Venise and a tawny port. The peninsula and an equally big area to the south make up the recently created Vinho Regional Terras do Sado, which is the source of some of Portugal's most exportable and exported dry red and white table wines. Jose Maria da Fonseca Successores is a family firm which bottles blended table wines such as Periquita and Quinta de Camarate while J M da Fonseca Internacional is most famous as bottler of Lancers, Mateus' big pink rival. Australian Peter Bright has done much to put this winemaking base on the map, notably with the full, dry Muscat João Pires from Bacalhôa Vinhos.

Alentejo

In a nutshell: Dynamic and good value.

Main grapes: Aragonez, Trincadeira, Castelão (red); Roupeiro (white).

The warm, dry Alentejo region in the south east is probably the country's most promising source of full-bodied, deep-coloured, accessible table wine, sold mainly as Vinho Regional Alentejano. Another Australian, David Baverstock, who tired of making nothing but port in the Douro, is exporting increasingly interesting wines from the large Esporão property. Co-operatives such as Borba, Granja, Redondo, Reguengos de Monsaraz and Vidigueira are some of Portugal's most energetic. But there are many exciting individual estates such as Mouchão and Quinta do Carmo (part-owned by the Rothschilds of Château Lafite), Quinta do Centro and special bottlings such as Peter Bright's Tinta da Anfora. Prices here are still reasonable and this is certainly one of the most promising wine regions in the world. Even whites can be interesting.

See ViniPortugal for more information on this region.