Spice girl: Kate Humble's aromatic journey in Indonesia

Nutmeg was once thought to cure the plague – but for European explorers, the journey to its source in Indonesia's Banda Islands was perilous. Today this remote archipelago is as intriguing as ever

There are many foods we consider so commonplace that we attach almost no importance or value to them. Yet the things we now take most for granted – the pepper on every kitchen table, the vanilla that flavours our ice cream – were once responsible for driving Europeans beyond the boundaries of their known world. Back in the 16th century, explorers were undertaking journeys which took them literally off the map, in search of spice islands.

Spices were known in Britain all those years ago, but their origin was a mystery. To reach London's docks they would have been passed from trader to trader, with the price increasing as much as a thousand times from its source to when they were finally sold on London's streets. Severe punishments were handed out to anyone trying to pilfer any, and stories of the magical properties of these exotic substances abounded. When word got out, in plague-ridden London, that a curiosity called nutmeg could cure any sufferer, demand rocketed. It was obvious that anyone who could find its source and control its trade would become very rich indeed. The quest for nutmeg, that little wrinkled kernel we now might grate into a fish pie or a Christmas pudding, changed the world forever.

Nutmeg, we now know, comes from Indonesia. Last year, I made my own journey to the source, while filming Spice Trail (to be screened on BBC2 from Thursday).

I had never been to Indonesia. On the map its 17,500 islands spread over a vast area of ocean make it a bewildering prospect, even for the modern-day traveller. Europeans didn't even know this area existed until the turn of the 16th century, when Portuguese traders established a presence here.

Then there was an even bigger problem: nutmeg didn't grow over the whole of Indonesia. Of those 17,500 islands it could be found on just six, in a tiny, remote group in central Indonesia known as the Banda Islands. From Java, the nutmeg hunters would have embarked on a relay of journeys, using locals to pilot them from island to island.

My search for nutmeg also started in Java – a 17-hour indirect flight from the UK, which is of course nothing compared to the year or more at sea endured by those early explorers. Even today, the Banda Islands are not easy to get to. Two more flights from Java got me to the island of Ambon, and from Ambon there is a twice-weekly flight to Banda Neira. Or not, if the plane is broken, as it was when I arrived.

There is an occasional ferry: a small overcrowded vessel that takes a gut-churning 24 hours to reach Banda. The option I was able to take was rather more pleasant. I made the journey on a privately owned traditional phinisi sailing boat. After 14 hours at sea, I caught a first glimpse of the Banda Islands that was probably little different from that seen by those pioneering Portuguese mariners.

We sailed into a natural harbour dominated by the volcano Gunung Api, which last erupted just over 20 years ago. The undersea lava flow is now one of the great dive sites of the area. If the volcanic soil and high humidity above the surface make the Banda Islands as lush and verdant a tropical idyll as I've ever seen, then the sun, warm sea and volcanic nutrients have all contributed to create one of the most staggering and pristine coral gardens I have ever dived in. The flow, still clearly visible on land, disappears beneath the water under a riot of giant corals as colourful and varied as a herbaceous border. This attracts not bees and butterflies, but thousands of fish of every conceivable size, colour and design.

Banda Neira, just across the channel from Gunung Api, is the main island, home to the airport, the market and 9,000 Bandanese who live largely from fishing and farming. And beyond the only town, the island is thickly forested with, among other things, nutmeg trees.

When the Portuguese reached Banda, trade was conducted with local chiefs, an often-protracted process which nonetheless allowed the merchants to depart with a cargo guaranteed to bring fame and fortune for life. But when the Portuguese were superseded in the early 17th century by the Dutch, things changed for the worse on Banda. The Dutch East India Company wreaked murderous havoc, turning Banda into a series of nutmeg plantations worked by slaves shipped in from Java.

Banda Neira today is a peaceful place, its clean, quiet streets devoid of any cars save a police van. People get around on foot, bicycle or moped. The simple houses are painted in fresh, bright colours, chickens scratch about in front yards and dogs lounge in the shade of the trees that put the island on the world map. There are nutmeg trees everywhere. They're rather pretty, medium-sized trees with rounded yellow leaves and fruits about the size of chestnuts that hang down on long stalks like fat, golden raindrops. When they ripen, the fruit splits to reveal a startling red interior.

Usman, who has an orchard of 200 nutmeg trees on the hill above the town, showed me how to pick the fruit using a basket on the end of a long pole. The red area forms a slightly waxy, petal-like structure covering the seed kernel in the middle of the fruit. This is mace, highly fragrant but more usually seen ground-up in jars on Britain's supermarket shelves, its brilliant red colour faded to a chestnut brown. The seed kernel it guards has a shiny exterior. Beneath that is the little, wrinkled nut that we call nutmeg.

So, what about the English? Where was this great seafaring nation that had as much of an appetite for nutmeg as anyone? Stymied by prevarication and royal politics, they didn't reach the Banda Islands until the Dutch had fully established themselves on all but one of the nutmeg islands. The one that remained is 10 miles away from the main group and is surrounded by a treacherous reef. Only two miles long by half a mile wide, it yielded more than enough nutmeg to risk its perils. In 1603 The English took it, much to the fury of the Dutch.

The island, which is known as Run, is as inaccessible today as it was then. However, the weather and the tides were kind to us and with expert sailing and reef-avoidance by our captain I made it on shore, five centuries after the first English explorers had arrived.

The land rises steeply out of the sea, leaving just a fringe of flat land along which lies the island's main street. There are no cars and the 100 or so resident families perch precariously on its forested sides in houses reached by a labyrinth of stairs and pathways. I wound my way upwards, past a giggling group of school girls who all asked for my autograph – simply because I was the strangest looking alien they'd ever seen.

A breathless climb brought me to the top of the ridge, where in among the villagers' plantations of bananas, papaya and nutmeg, I found a few crumbling ruins. There were the remains of a few steps and the walls of what might have been a house, long overgrown by trees and weeds and used as a hangout by some goats. These are the only reminder that this island was once under English control.

Not that the English controlled it for long. Hot on their heels came the Dutch, who seized it from them. It remained more or less permanently in Dutch hands until, in 1616, a British captain called Nathaniel Courthope came to claim the island once again for James I. The locals, who by now loathed the Dutch as much as the rest of the people of the Banda Islands, were only too happy to give the Englishman as much nutmeg as he wanted in return for protection against the Dutch. A deal was struck. King James adjusted his title to declare himself King of England, Scotland, Ireland and Run. The island became England's first colony.

It wasn't long before the Dutch came to take it back. Courthope (whose exploits are described by Giles Milton in Nathaniel's Nutmeg: How One Man's Courage Changed the Course of History, published in 1999) held on to the island for four years until he was ambushed at sea and killed. For the next half-century the two nations wrangled over this tiny patch of forest. At one stage in the conflict the English sailed across the Atlantic to capture the Dutch-held island of New Amsterdam.

There was a stalemate until some bright spark suggested that both sides simply hold on to the islands they had seized, leaving the Dutch with Run. In 1667, with some reluctance, the English acquiesced. They turned their back on the spice islands and hoped their fortunes might lie further west, with the island they now renamed New York. Run is the reason the citizens of America's greatest city speak English, not Dutch.

These days it is almost impossible to imagine that any of this happened. The islands seem like little tropical idylls, their traditions and cultures intact. There's little lasting colonial influence, as if as soon as the English and the Dutch left, life returned to the way it had always been. The people of the Banda islands still make their living from fishing, heading out at dawn in the shadow of the volcano in tiny, painted boats and returning with their catch to sell in the local market. Every family still has nutmeg trees, which they treat almost like a bank account. If they are short of funds they will harvest the fruit, make jam or candy from the soft outer-casing and carefully separate the mace and nutmeg to dry before they sell them to the local trader.

I joined a group of women gathered on the front porch of one of their homes to help process their nutmeg. They talked about their children, their husbands, the weather and why I had such weird hair.

Tourism isn't much relied on; the transport to and from the islands is simply too unreliable, and once you get to them, there's little to do. There are a couple of guesthouses, a walk to the peak of the volcano, and the chance to swim in a bath-warm sea while frigate birds soar overhead. But the intense heat and suffocating humidity allow for little more than sitting, sweating and looking at the view.

As I did just that, from the look-out on Run, I understood the sheer scale of the achievement of those early pioneers. Of course, it wasn't long before nutmeg seedlings were taken from the Banda islands and cultivated in other, more accessible parts of the world. These tiny patches of land that had suffered so much as the exclusive home of nutmeg were left to slip slowly back into obscurity; a group of rugged, tree-covered islands in the midst of a wide, dark, forbidding sea.

'Spice Trail', presented by Kate Humble, starts on Thursday on BBC2 at 9pm

Travel essentials: Banda Islands

Getting there

* Fly to Jakarta from the UK with KLM (08705 074074; klm.com), Qatar (0870 770 4215; qatarairways.com), Singapore Airlines (0844 800 2380; singaporeair.com) or Emirates (0844 800 2777; emirates.com) via their hubs. Fly to Ambon with Lion Air ( lionair.co.id). Reach Banda Neira on NBA Airlines or Pelni Ferries.

Red tape

* British visitors can get a visa on arrival for US$25 (£16.70).

Spice world: The global taste test

Pepper

The pepper we all have in our grinders is the berry of piper negrum, a vine-like plant that originates in Kerala, southern India. Its source was found by the celebrated Portuguese navigator Vasco da Gama in the late 1400s. Today the plant is under threat from a disease known as wilt, which causes the pepper vines to do just that.

Cinnamon

True cinnamon grows only in Sri Lanka and again, we have the Portuguese to thank for revealing its origin. Cinnamon comes from a tree. The branches are coppiced, the outer bark peeled in the same way you might peel a carrot, and then the yellow inner bark is stripped off and left to dry. It is then layered and rolled to create the cinnamon sticks we are familiar with. It is a long, slow and skilful business.

Saffron

The world's most expensive spice, which sells for about €4,000 a kilo. Saffron is the stigma of a species of crocus. Each bloom is picked by hand, the stigma carefully removed and dried; 200,000 flowers make 1kg of saffron. Today it is grown in various countries including Iran, Kashmir and Morocco. Spain claims to have the highest quality saffron. There is a huge market in fake saffron.

Vanilla

Contrary to popular belief, vanilla originates in Mexico, not Madagascar. It was introduced to the world by the Spanish explorer Cortés. For 300 years it would not grow anywhere else because to fruit, this orchid has to be pollinated by a tiny species of bee found only in Mexico. It wasn't until hand-pollination was discovered by a 12-year-old slave boy on Réunion island that it was grown elsewhere.

Cloves

These are the dried flower heads from the clove tree. Like nutmeg they come from a tiny handful of islands in Indonesia called the Moluccas. They are now also harvested in Madagascar, Zanzibar, Pakistan, and Sri Lanka. Most of Indonesia's cloves are used to make their best-selling brand of cigarette – the Kretek.