Thanks to Portugal, English intellectual life survived the 18th-century conflicts with France, bequeathing to us the port-nourished works of the Augustan poets and the garrulous high culture of Dr Johnson's port-bibbing London. The English colonists who settled on the Douro, to produce a wine that was not liable to the heavy duties levied on the wines of France, lived there in expat splendour. They seldom fraternised with the natives, who toiled on the slopes and stamped in the wine presses, with the blood-red juice swamping their thighs but no fair share of the profits.
Whether the winemakers urinated in the vats, I do not know; but our ancestors deserved it if they did. Now, with EU membership, the workforce has fled for the suburbs of Paris and those feet are no longer available to press the grapes. Speculation is rife as to whether vintage port will survive the change.
The aroma of human labour is still there in the sweaty wines of the Quinta de Covela. The white is a blend of the native Avesso grape with Chardonnay and Gewürztraminer, producing a richly perfumed wine with all kinds of earthy aftertastes that brought wrinkles to the brow and tears to the eye as we struggled to identify them. "Toenails" was the word that at last came to mind, suggesting that the old methods have not, after all, been entirely abandoned. The rosé is less an aperitif than a serious dinner wine - a tough blend of the local Touriga Nacional with Merlot and Cabernet Franc, made by bleeding the colour from the skins before running off the must for its final fermentation. There is enough tannin, we discovered, to give the wine the backbone needed for a contest with a greasy joint of pork.
The Quinta do Ameal from the Minho region is made from the Loureiro grape - staple of the familiar vinho verde. This is an attempt to make a serious wine from an unserious grape, and it is as successful as that implies - light, refreshing, gently perfumed, but with a sharpness and tang that went well with Leonard Bernstein's Age of Anxiety, broadcast from the Proms.
In our view, however, the best of these four wines is also the cheapest - the Quinta de Chocapalha from the Estremadura. This wine, made by the stunningly beautiful Sandra Tavares da Silva Borges, is as long-winded as her name, dawdling on the palate like a group of leathery peasants beside a waiting train, to be carried into the tunnel still waving and burping from the encroaching darkness. Cabernet Sauvignon is mixed with the local varietals, Touriga Nacional, Tinta Roriz and Alicante Bouschet, giving a vitality that is not always to be encountered in Portuguese reds. And its strength (14.5 per cent) means that it stays fresh and enticing long after being broached.