They live what can only be described as a "pampered and gullible agrarian existence": strangely reminiscent of Marie Antoinette before the guillotine.

It's late November now in the north-west corner of Andalusia, but this fine weather would pass as high summer in many parts of Europe. And this UNESCO-protected landscape is just to die for, literally.

Not that the black pigs care. Their focus is solely on the fact that it is feeding time.

They have obviously learned to trust Manolo, their weather-beaten Andalusian handler.

Even now he's beckoning them with strange guttural grunts and squeals that sound like some porcine dialect, letting them know food is on its way.

He's carrying a long stick, but it is in no way threatening. He uses it benignly to knock scores of acorns out of each selected tree. As they crash to the ground, the 20 or so porco pretos rush round, greedily gobbling up each one.

Again, in their innocence, they don't realise there is order in the way Manolo chooses to rattle each tree.

Apparently, the acorns from the cork trees are more bitter than the sweeter ones from the holm oaks, and the pigs need to feast on a balance of both. They're not just being fattened up, but being finely flavoured for the tables of the world.

For two years, these same pigs have roamed free in a portion of the Sierra de Aracena Natural Park, so revered for its constant temperature, unchanging climate and exquisite landscape that it has earned World Heritage status.

For most of that time, they've supped on whatever they could forage, each one allotted the equivalent of a soccer field of perfect Spanish countryside.

But now, in their final five months, they're hitting the acorns with abandon.

They might not know their fate, but Manolo does. For the pigs, it must be the most intimate of betrayals.

One morning, very soon, they will gather as normal to follow Manolo, just as those children followed the Pied Piper in the fairy story about the greedy humans of Hamelin all those years ago.

Manolo's boss, Domingo, will make sure their final hours are as peaceful as possible. As Domingo explains during our two-hour tour of the family-owned ham-processing factory, any distress the animals might suffer would be revealed in the flavour of the ham. And we wouldn't want that, would we?

So when the pigs travel the short 15 kilometre journey from paddock to abattoir, the accent is on a humane, dignified death. First they're gently gassed and rendered unconscious. Then they are administered a lethal electric shock. No time for sympathy, let alone a squeal.

It has taken our party three days to drive from Lisbon to the picturesque village of Corteconcepcion, midway between the Portuguese border and the stunning cathedral city of Seville. That's because we have taken the "road less travelled", passing through pretty  town after pretty town on the "old" route instead of taking the highway to our easternmost destination, Cordoba.

We've seen plenty of porco pretos since we left Lisbon, but usually in ones or twos, and always accompanied with a loud squeal from someone on our luxury coach: "Black pig!"

Some of us have even eaten "black pork" at one of the Portuguese restaurants we'd visited before we crossed the border.

But then there's a reason why this delicacy is called jamon iberico, after the entire Iberian peninsula: both Portugal and Spain produce it - and each traditional ham producer jealously protects its manufacturing techniques.

Jamones Eiriz in Corteconcepcion, however, is an exception. Having operated in secret for the past 200 years, it opened its doors to the travelling public less than five years ago, recognising that the same people who love visiting wineries would also love to see how their Christmas ham is produced.

The family now operate daily two-hour tours in English, Spanish and German (booking is essential), which can be combined with visits to a cheese factory and a traditional distillery all within a 12 kilometres radius. Jamones Eiriz also features on the Jabugo Route, a five-day walking and degustation tour (see rutadeljabugo.travel).

There's a difference, though, between a grape being crushed and an animal being processed - even for a meat-eater like me. So be warned: this is not a tour for the squeamish. The odour of animal fat is part of the curing process, but hard to stomach for very long.

At the entrance to the ham factory - which is the size of a farmhouse plus a couple of barns - we are each asked to don a disposable hat, disposable smock and disposable overshoes. That alone should have made it clear that this is not the typical foodie tour.

The production process is quite easy to understand. The black pigs are taken to the abattoir, killed humanely, and divided into those parts which are returned to Jamones Eiriz (essentially the four legs and the back of the animal) and those less desirable parts which find their way to normal Spanish butcher shops.

Domingo shows us what happens when the various porcine limbs return to Jamones Eiriz. We are taught how the meat from a black pig backbone is made into a gourmet range of sausages and salamis. How the hams have to be semi-immersed in a stockpile of salt for several days, being turned regularly. How the various meats are "cured" (and what a wondrously misleading word that is).

Our final stop, before gratefully emerging into fresh air, are the various drying rooms where  the hams (still with their distinctive trotters attached) are hung up to age for weeks at a time.

Domingo explains why the floors of the drying rooms haven't been cleaned, meaning they are still covering in a layer of grease caused by fat constantly dripping from the hams. In time, Domingo says, that fat on the floor evaporates and is absorbed back into the hams, part of the natural flavouring cycle.

At this point, I realise I probably know more about Iberian ham production than is good for my health. It's like that old adage about sausages: if you want to continue enjoying them, don't ask how they are made.

But any doubts that I may have about being put off ham for life are soon dissipated. In the pretty, multi-flowered courtyard outside, Domingo's staff have assembled a sumptuous smorgasbord of their different hams and sausages, plus local cheeses, wines (from the Huelva region) and sherries.

Suddenly my appetite returns. And as we enjoy the winter sunshine and the scent of fresh flowers, it is easy to be tempted by slither after slither of jamon iberico and chorizo.

I can't say that I can taste the acorns, but I definitely taste those porco pretos!

TRIP NOTES

MORE INFORMATION

See jamoneseiriz.com.

GETTING THERE

Emirates Airline has daily flights from Sydney and Melbourne, via Dubai, to Lisbon and Madrid, with connecting flights to Seville with Iberia Airlines. See emirates.com.au.

TOURING THERE

Insight Vacations' nine-day Amazing Spain and Portugal visits Madrid, Granada, Seville, Lisbon and Salamanca. Priced from $1975 per person, twin-share including a Signature Experience learning about the history and curing process of Jamon Iberico. Also includes eight nights' accommodation in luxury, centrally located hotels, an experienced tour director, Signature Experiences and priority access, business class legroom and smaller groups, free Wi-Fi and airport transfers. Departures available throughout 2015. See insightvacations.com or call 1300 301 672.

BUYING IN AUSTRALIA

Jamones Eiriz has just started exporting its first hams to Australia, via a Brisbane company, General Exportaciones. See generaldeexportaciones.com/spanish-jamon/

The writer was a guest of Insight Vacations.