On farms all over the western Midlands, Gloucestershire Old Spots pigs are being spruced up for their annual show and sale, due to take place at Ledbury on 17 April. This will be the third show organised by the GOS Pig Breeders' Club, and it will mark a further stage in the rehabilitation of a splendid animal.

An Old Spot - the "s" is normally dropped in everyday usage - is a heavy, lop-eared creature, with big, black splodges on a whitish background. The breed was not formally registered until 1913, but everywhere in our part of the country - in pubs, on postcards, on trays - there are representations of spotted pigs taken from paintings at least 150 years old, and it is clear that the animals, or something like them, existed early in the 19th century.

Thirty years ago the breed declined to a low ebb, but now it is strongly in the ascendant, owing partly to the enthusiasm of a few dedicated farmers and partly to the reaction of consumers against the pallid pork which is all that supermarkets are prepared to handle. Old Spots are recognised as endangered by the Rare Breeds Survival Trust, but the club now has more than 600 pedigree sows on its register.

Among modern owners, few are keener than Eric Freeman, who keeps the pigs on his farm at Taynton, near Gloucester. As he puts it: "They're much the happiest living in the open, so they lend themselves to the movement for eating animals that have been looked after kindly, and naturally fed." Also, he says: "They're quite characters, some of them. What they get up to - sometimes you can't help falling on the gate and laughing."

In earlier times Old Spots were known as orchard pigs, because they lived in the cider orchards of the Severn Vale, grazing the sward in summer, rooting among the trees, and guzzling on windfall apples in the autumn until (it was said) their meat acquired a magically sweet flavour. Legend has it that the black spots were originally bruises, caused by the impact of falling fruit.

Another staunch fan was the late-lamented Jasper Ely, who had an orchard at Priding, beside the Severn, and I shall never forget the Hogarthian scene in his cider shed when the harvest was coming in. Casks full of last year's brew were ranged along one wall. At the far end, two young men would be toiling at the press that squeezed the apple pulp. The floor was running with juice. Jasper himself, his halo of white beard and hair surmounted by a blue nautical cap, was propped against a doorpost, tankard in hand, shouting out: "Don't fuck about, you two! Keep turning!"

The smell of apples blended inextricably with that of pigs, for over a wooden partition a huge sow was suckling her litter. A man with a squeaky voice kept announcing: "Old Spot sow wi' thur'een on 'er!" and every now and then somebody tipped a bucket of crushed apples over the wall, so that by nightfall the sow was as high as the men were.

Jasper used to collect spent grain from the brewery in Uley, a village nearby, and feed it to his pigs. When Chas Wright, the brewer, brought out a chocolate-dark strong ale, there was only one name for it. As he points out, many strong ales are called "Old Something" - Old Peculier, Old Roger, Owd Bob - because they are traditionally matured before going on sale.

Thus the new beer inevitably became Old Spot - as did a pub in the town of Dursley, when Chas took an interest in it. Last year the Old Spot was runner-up in the National Pub of the Year competition - and so, one way or another, the name is going strong in the county. Yet it is the excellence of their flesh, rather than sentimental memory, that is really bringing spotted pigs back. To Andy Binks, a butcher now working at the Chesterton Farm Shop on the outskirts of Cirencester: "They give an old-fashioned meat, firm, with a good grain and real flavour. The pork you get from commercially grown pigs just has no fat. Unless you've got apple sauce with it, if you shut your eyes you wouldn't be able to tell what you're eating.'

One important difference lies in the fact that the Old Spots handled by Chesterton's are all free-range. Another derives from the way in which the pigs' carcasses are treated after being slaughtered - and here sounds a fascinating echo of William Cobbett, the vociferous agricultural reformer and champion of the poor, who flourished at the end of the 18th century and the beginning of the 19th.

Cobbett urged every cottager to keep a pig as a vital part of the domestic economy, and he was adamant about its preparation for the table. The bristles, he laid down, must be removed from the skin by burning rather than by scalding, because the taste of meat from a singed hog was far superior to that from a scalded one. He therefore gave precise instructions as to how the freshly killed pig should be "laid on a narrow bed of straw, not wider than his carcass, and only two or three inches thick. He is then covered all over thinly with straw, to which, according as the wind may be, the fire is put at one end." Today the method is more refined, but the aim is exactly the same. Whereas in big slaughterhouses pigs are scalded in boiling water, those destined for the Chesterton shop are kept dry, the bristles being scraped and shaved off. The result is crackling such as most people have never tasted.

The pigs shown in old paintings have barely credible dimensions: bloated rectangles teetering on tiny pins, they could hardly have survived if they really had been that shape. You long to know how they would have squared up against Foston Sambo the 21st, the Old Spot who holds the record for the highest price paid for any pig in Britain; he fetched 4,000 guineas (pounds 4,200) when sold at auction in 1994.