The best old ham comes from acorns

There are fine arguments to be had when it comes to ham: not least of those religious arguments which hold that a pig is an unclean animal and should not be eaten. Why more unclean than another is hard to discern. Trichinosis, caused by a hairy worm, the trichina, that infested man and hog alike some time ago, is long gone; but the prohihition remains.

Most arguments about ham these days are national, ham being the natural, long-lasting, relatively easily preserved part of a porker, and thus vital to the agricultural interests of many nations - France here being, culinarily as agriculturally, the exception.

Having written about ham in general back in August, I am here looking at one of the two commonest hams on the market, prosciutto - the other being the Spanish jamon serrano.

Spaniards of my acquaintance consider prosciutto rather effete. It lacks manliness and asceticism, a sense of soil, the vigour of chivalry and so on. They may well be right, for Italian prosciutto, at least as we know it now, is a far cry from basic smoked, salted or air-dried ham. During the past few decades it has become delicate, succulent and perfumed according to rigorous standards, and one has to travel far and wide to find the older, more authentic Italian prosciuttos.

What makes prosciutto distinctive from other hams is its moisture content, its high proportion of fat, and the way it is cut (ultra-thin) and prepared (highly polished and smoothed). Next to this glossy product, a jamon serrano is positively rustic: a chunk of meat on a bone to which you take a knife and cut a chewy chunk of wonderful, primitive flavour. It goes with that hardbaked dry bread the Spaniards produce, eaten dry; while prosciutto follows the Roman prescription and is eaten with fruit such as figs or melons.

All this proves is that prosciutto is another triumph of Italian design (and marketing), and that making simple things attractive is a singularly Italian art. No slicing with a knife for Parma ham. What we eat has been beautifully and evenly sliced by machine, and most of it comes pre-sliced and vacuum-packed.

Waverly Root, whose guide The Food of Italy remains (while other books have come and gone) a classic of the genre, now has a certain antiquarian fascination. The eating he did in Italy, which led to the first publication of his book in 1971, preceded the great industrialisation of Italian food, the rise of vast consortia such as Parmalat. He is astonished by the production of prosciutto di Parma, the classic ham: 150,000 hams a year. This year, he would be astounded to know, production reached nearly 60,000 tonnes or approximately a million hams, a billion-pound industry and still growing.

Now, the ham made leaner than ever by feeding the pigs on a diet of soya, it is heading for Japan, Canada and other ultimately politically correct markets. The United Kingdom comes last in consumption, with a mere 215,192kg against nearly 3 million kilogrammes in France, half that in Germany and a half-million in the United States; but we are the fastest growing market, up 36.2 per cent.

There is, of course, a gastronomic price paid for commercial success. Not the least cost to us as consumers is the driving from the market of the much wider variety of Italian hams which Root was able to sample, though again Italian marketing is such a refined instrument that several regional hams, especially my favourite, the delicate San Daniele of the Friuli, are making notable advances. But what of Parma ham itself? I am not alone in thinking it has become too bland by half. In Root's day, pigs destined for prosciutto were fed mainly on the whey left over from the production of their prestigious neighbour, parmesan. They were also more heavily salted.

The San Daniele pig is still fed on acorns; he is not kept indoors. As a result, his meat is leaner and has a more clearly defined taste. Ageing is also a factor. Commercial Parma ham is ordinarily marketed between three and six months after preparation, which I call impatient. A year is better, and more than that produces unequal, but sometimes superb, results.

Parma ham is a delicacy in any form, one of my favourites being the Roman (but originally Lombard) saltimbocca: a thin slice of veal rolled around succulent ham. Its inexorable combining with melon I deplore except when the fruit is ultra-ripe and sweet, and preferably with lightly chilled honeydew, not the inescapable cantaloup.