Every year, hundreds of refrigerated lorries leave the vineyards of Spain, Sicily and southern Italy carrying trays of wine grapes to Italians in exile. Italians first came to settle in Britain over a hundred years ago. Indeed, it's an emigration that has only died out over the past 25 years as the gap between the two countries' prosperity has narrowed. For the older members of the Italian communities, who mostly came here to make ice-cream, run restaurants and coffee bars and lay mosaic floors, home winemaking has an almost ritual importance.
It's carried out in surroundings which would defeat most professional winemakers, without a thermometer to check fermentation temperatures or a hydrometer to measure alcohol levels, and with no dried yeast or tablets of the all-purpose disinfectant sulphur dioxide.
Instead Luigi Tambini, who's 59, insists that the key to success is finding the right raw material - difficult when you have nothing but its physical appearance to go on. Like most serious winemakers, Luigi believes in what the French call terroir, the principle that the quality of the wine depends on the place the grapes are grown. But, living hundreds of miles away from the vineyards, he has to depend on intermediaries and, as one former importer, Tony Demarco of the wholesalers Mamma Roma, told me: "You get a lot of cowboys. A lot of people try to get the cheapest stuff and make the most money, and they can get away with it because it's only a once- a-year business. There's no comeback."
As he does every year, Luigi began looking for likely grapes in mid-September. The first fruit of his researches was some seedless white Sultana: a variety mainly associated with table grapes and dried fruit, but also used for winemaking. Then, at a wholesaler's in Tottenham, Attilio came across a supply of red Sicilian wine grapes: small, deeply coloured, intensely flavoured and free from rot and spoilage. Attilio snapped up 34 10kg boxes at pounds 5.50 each, while Luigi bought 118: enough, he estimates, for 750 litres of wine to keep him supplied for the coming year. A Customs & Excise spokesperson confirmed that even this large volume will be exempt from duty given that it is for personal use.
The figures look good. A litre of Luigi's 1998 red will have cost him just over 85p. But he insists that the money isn't the only point: "Two glasses of the wine you buy in the shop and I'm already drunk. There's got to be something wrong with that. But this ... this is a proper grape wine." He finds that the sulphur-free wine causes no ill effects, even in fairly copious quantities. "I drink at least two litres a day, and every night my wife drinks two glasses."
Luigi came to London in 1959 from a village near Parma in northern Italy. He worked in restaurants and ran a sandwich bar in Russell Square before his current job as a driver for a company making terrazzo flooring. His current job also involves long hours which is why, with regret, he has gone from treading his grapes to using a manual crusher, putting a proportion into a traditional wine press to improve the extraction of colour. The red wine ferments under a "cap" of crushed grapes in open-topped plastic barrels for a fortnight; then Luigi runs it off into 55-litre glass demijohns, siphoning it after a further 10 days into clean demijohns, on which he floats a layer of olive oil to seal it from the air. Bottling always takes place on Good Friday, when there's a waning moon; a new moon is reputed to expel the corks. He is adamantly opposed to using dried yeast or additives of any kind: "I make it the way my father showed me in Italy," he says.
Luigi's technique gives him quite a light-coloured wine, still slightly fizzy in the bottle and not unlike the dry Lambrusco of his native province, Emilia Romagna. Southerners, he says, take a slightly different approach, stirring the wine and pushing down the cap of grapes to speed the fermentation and to extract more colour.
The wholesaler Tony Demarco, whose family comes from Calabria, in the heel of Italy, comments: "Every family has its own way of doing it and every family is convinced it makes the best wine." Luigi fears that if he stirs in the grapes it would turn the wine sour, as the mass of grapes on top becomes distinctly vinegary. The top few inches of the barrel in which the wine ferments will also provide the raw material for his excellent vinegar.
Few experts would be too impressed. Merlin Holland, the author and wine writer who is the grandson of Oscar Wilde, was inspired to take up home winemaking after a Christmas party given by an Italian printing firm, where one of the staff had brought a demijohn of his own wine. He comments: "It had a beautiful red colour, but it was disgusting. Quite undrinkable - though you could tell there had been some decent fruit to start with." Don Lewis, the award-garlanded winemaker at Michelton in the Australian state of Victoria, calls the style favoured by Luigi and Attilio: "Oxidised and acetic (ie, vinegary) - but that's the way they like it."
Lewis is familiar with the stuff through the Italians whose arrival in Australia after the Second World War helped trigger his country's wine boom. And Italians played an even more significant part in the American wine industry. California's vineyards largely survived Prohibition by sending huge quantities of grapes across the continent to east-coast Italian immigrants who were given an exemption for home winemaking.
Here, the tradition is in danger of dying out (Luigi says his son didn't like to see him foot-treading the grapes). Among Britain's Italians, abandoning home winemaking is seen as possibly the single most crucial indicator that they are merging their identity into the wider community. But in London's Clerkenwell delicatessens there are still wine presses and demijohns for sale each autumn. And in Holloway, Tony Demarco is making plans to restart shipments from southern Italy. He says the trade in wine grapes is actually growing: "Not with the Italians, but with the newer immigrants, the Spanish and Portuguese. Show me a single Portuguese family that doesn't make wine."
The Italians' example has led to a wider resurgence of home winemaking, using real grapes rather than the concentrates and chemicals that were popular in the 1970s. Wholesalers are also seeing a growing number of African and Caribbean customers for wine grapes. Merlin Holland has made more than 100 litres of wine every year since 1981, though these days his raw material is Pinot Noir grapes he drives over from Burgundy in the back of his car. Recently, he says, his winemaking method has moved closer to the low-tech style of the Italians: "Over the years you learn that you can do much less and still get away with it."
As they work on the 1998 vintage, both Luigi and Attilio press glasses of last year's wine on me. This rather bitter stuff, drunk from brimming tumblers, has a tingle of dissolved carbon dioxide and is not wine as we know it from supermarkets or wine merchants. But the spirit behind it is one that would be recognised by many wine enthusiasts. Simon Loftus, the chairman of Adnams, one of Britain's leading wine merchants, insists that wine should be seen, not as a work of art, but as "an agricultural product designed for straightforward enjoyment".
Luigi's red wine is certainly not a work of art, but it's oddly more- ish and memorable. Are you pleased with the 1997 wine? I ask, tentatively. "Am I pleased?" Luigi is baffled that I should have to ask. "Am I pleased?" He looks hard at me, tips back the remains of his glass and beams. "You bet I'm pleased".
Patrick Matthews is the author of `The Wild Bunch - Great Wines From Small Producers' (Faber, pounds 7.99), which won this year's Glenfiddich Award for drinks book.