South Africa is not the first country to be embroiled in a wine scandal, but the news that the KWV, one of the biggest producers in the Cape, is facing possible legal action after it was found to have added artificial flavourings to two batches of Sauvignon Blanc to enhance the variety's easily recognisable gooseberry and cut grass characters, is still a worrying bit of skulduggery.

The fact that the whistle-blower was the South African Wine and Spirit Board, rather than a jealous competitor, is a mitigating factor, but it's amazing how much damage bad publicity can do. Take the 1985 Austrian di-ethylene glycol scandal, which still prompts comments about anti-freeze from consumers at generic tastings.

How common are such scandals? Like any other multi-billion pound international business, the wine trade has its share of crooks. But most of the stuff that ends up in your glass is honestly made and labelled. In fact, given the size of the wine business and the potential for cheating, as large volumes of unbottled liquid move around the world, it's amazing that producers are so straight.

There are constant rumours of nefarious goings-on: the grower who adds oak chips to his white Burgundy; secret night-time deliveries of Sicilian plonk to a co-operative in south-west France; the Spanish producer with a vat of vanilla essence at the back door; the Australian winery that adds tins of peaches to its Chardonnay.

Such rumours are easier to believe than they are to substantiate, however. At least they are if you don't want to wind up swimming with the fishes. Journalists who ask the wrong type of questions tend to get warned off pretty sharply. Even so, the odd scandal makes it into the papers. Sometimes it's the local fraud squad that fingers the cheats, sometimes it's a nosy neighbour, and sometimes it's just a matter of chance. A dodgy cache of Bergerac rouge was found a few years ago when the van driver transporting the wine was stopped for speeding. Best of all, the di-ethylene glycol scandal came to light when an Austrian producer tried to claim a tax rebate on the stuff he'd been blending into his wines.

Creative blending, or labelling, still happens. Wines from different regions or countries are used to add structure or colour to sub-standard vats; generic wines like Côtes du Rhône or Chianti are quietly 'promoted' to something more expensive like Chteauneuf-du-Pape or Brunello di Montalcino; good crops are 'extended' by adding wine from subsequent years. The 1970 vintage in Rioja, for instance, widely regarded as an annus mirabilis in the region, was notoriously elastic.

Most of these things are misdemeanours rather than crimes, in my view, especially if they improve the quality of what's in the bottle. The only really bad thing that's happened in recent times was the 1986 Italian methanol scandal, which killed 21 people. No one ever got to the bottom of this one: did the four producers concerned add methanol to increase the alcohol level of their wines (and leave the tap running for too long)? Were the wines intended for EU distillation rather than human consumption? Or was the whole thing a Mafia plot?

Could something like methanol happen again? It's unlikely, to be honest, especially if bodies like the South African Wine and Spirit Board stay vigilant. But the pressure on producers to meet the demands of retailers can only encourage them to cut corners. One thing is for sure: dodgy Cape Sauvignon Blanc won't be the last wine scandal I'll report on in these pages.

Six wines: Scandalously good buys

2002 Piesporter Goldtröpfchen Riesling Spätlese, Weller-Lehnert (£5.99, Majestic)

2002 was an excellent vintage in Germany, and this is an outstanding young Riesling at a giveaway price.

2002 Domaine de Roally, Viré-Clessé (£12.95, Lea & Sandeman, 0207 244 0522)

Made by the brilliant Jean Thévenet, this will change your mind about lowly Viré. It's a rich, concentrated white Burgundy, with the emphasis on fruit and stony minerality.

2003 Lone Range Pinot Noir, Martinborough (£13.99, M & S)

Produced in one of the best areas for Pinot Noir, this is a textured, sweetly fruity young red with just the right amount of fragrance and elegance.

2001 Barbera d'Alba, Cru Serraboella, Cigliuti (£17.75, Berry Brothers, 0870 900 4300)

This was one of my most exciting wines in 2004, despite the fact that it's made from the lowly Barbera grape.

2001 Boekenhoutskloof Syrah, Franschhoek (£24, selected branches of Waitrose)

You might have to go on-line to track down this first-rate red, buit'll be worth the effort. Marc Kent is the Cape's best Syrah producer.

My best buy

2001 Chteau Courac, Côtes du Rhône (£6.45, Jeroboams, 0207 259 6716)

This has to be one of the best value southern Rhône reds in the UK at the moment.

Famous drinkers: Edgar Allan Poe

'For what disease is like alcohol!' proclaimed Edgar Allan Poe's alcoholic narrator in The Black Cat, one of many references to alcohol found in the macabre American author's writings. Poe quickly became violent and irrational and would then drink until he either passed out or had spent all his money. His alcoholic father, a travelling actor, who died in 1812 when Poe was three, would regularly go on stage drunk.

Poe drank when he got depressed. Whenever he tried to give up alcohol something would set him off again, such as his wife's tuberculosis. He died mysteriously in 1849 at the age of 40. He left his home in Richmond for New York but only made it as far as Baltimore, where he was found passed out, drunk on the street. He died in hospital. His last words were: 'Lord help my poor soul.'
William Lee