Buying a cone? Don't expect it to contain real vanilla. The beans can make and break economies, writes Arminta Wallace

It was once the Cinderella of ice-cream flavours. Now, next to saffron, it's the most expensive spice on earth. In Madagascar and Mexico peasant farmers mount armed guard on their crop as harvest time approaches: with the price for gourmet-quality beans set at more than €400 a kilo, men carrying harvested pods to market have been murdered for nothing more than a couple of handfuls.

At the other end of the production line US importers can't afford to insure large stocks in their warehouses. One company was forced to split its stock in to three separate warehousing units by an insurance company worried that an accident would wipe out the firm's entire profit at a stroke.

Oh, yes: times have changed for plain old vanilla. A new book reveals that this unprepossessing plant is at the centre of a multimillion-euro trade so lucrative - not to mention secretive - that industrial flavouring companies make vanilla dealers sign confidentiality agreements, promising never to reveal that vanilla is an ingredient in their products.

Does Coca-Cola, for example, contain vanilla? Industry insiders say it does. One story doing the rounds in the vanilla trade is that New Coke, the disastrous reformulation of the soft drink that the company launched in 1985, was a vanilla-less version created in an attempt to escape the tyranny of fluctuating vanilla prices.

The company is said to have confidently sold off its stocks of vanilla. When consumers roundly rejected New Coke the company was forced to return to the original recipe and buy the vanilla back - at a higher price.

It may be just a yarn - Coca-Cola, famously, declines to comment on anything to do with its manufacturing process - but it's a good one. In fact, as a topic, vanilla is nothing short of fascinating. The vanilla vine is a member of the orchid family that is native to Mexico, grows only in the tropics and has to be pollinated by hand. It's the ultimate slow food. The pods - or beans, the terms are interchangeable - take nine months to grow, and drying and curing them takes another nine.

Vanilla pods were used as an aphrodisiac by Aztec emperors, who put them in their hot chocolate (times have clearly changed for aphrodisiacs, too). Nowadays the flavour drives foodies bananas. Sweet, floral, woody, nutty, marshmallow, leathery, dusty, smoky, strawy - strawy? - creamy, rummy, even mushroomy are just some of the words that have been applied to vanilla by devotees determined to pin down its subtle scent.

Chemists hell-bent on inventing a synthetic version of vanillin, the compound that is vanilla's essential constituent, identified more than 400 components within the natural bean. Synthetic vanillin is what you'll find in bottles of "vanilla essence" and most mass-produced ice cream.

Food industry heads insist that it's composed of exactly the same molecules as the natural kind, but come on, guys, who wants to slurp a mixture of clove oil, waste-paper pulp and coal tar?

The author of Vanilla: Travels In Search Of The Luscious Substance, Tim Ecott, followed the vanilla trail from Mexico to Madagascar, Kalamazoo to Kew Gardens. Born in Newtownards, in Co Down, he was educated in Bangor before his family moved to South Africa. For many years he worked as the BBC World Service correspondent in southern Africa and the Indian Ocean states, which is where he first came across the vanilla vine.

"I'd like to put it on the record that my life isn't spent obsessing over vanilla ice cream," he jokes on the phone from his home, in London. "It all began as a connection with a region of the world that I know well and have a great affection for." Ecott is also the author of a highly praised book on diving, Neutral Buoyancy.

But vanilla is a very different world - a different planet, almost. It took him a long time to get vanilla dealers to trust him, let alone take him in to the field with them. Now, he says, they're still sending him e-mails asking if he has heard about so-and-so or such-and-such.

"The market is still very volatile," he says. "And with the price having gone up so much in the last three or four years the fear is that it's going to crash as quickly as it rose."

So what's in the book? A lot of stuff about the history and politics of exotic places. Snippets about the international food industry. A flavour of English enthusiasms of centuries past, including a passion for plant collecting that puts Gardeners' World in the halfpenny place.

Then there are the vanilla bods. There's the woman who calls herself the Vanilla Queen, Patricia Rain - check her out online at www.vanilla.com. There's Madame Chane, a tight-lipped ethnic Chinese dealer based in Tahiti, who tells Ecott that talking about vanilla got her brother killed. And there's Henry Todd, "tall, dark and quite handsome", scion of the family-run company that buys almost half of the world's vanilla beans each year.

As portrayed by Ecott, Todd is urbane, intelligent and a good man to be marooned in the jungles of Madagascar with. He certainly doesn't come across as the model of a ruthless multinational operator whose main aim in life is to cheat the world's vanilla farmers out of a living wage.

Nevertheless it's the people who actually grow vanilla - men and women struggling to make a living in the remotest regions of some of the poorest countries on earth - who emerge as the real stars of Ecott's book.

And it is they who, while getting a mere fraction of the money that is changing hands in the vanilla trade now that prices are at their highest, will suffer most if prices collapse.

Which leaves the well-meaning Western consumer with a dilemma. How can we help?

"In global terms it's like any organic product," says Ecott. "You're doing more good in the long term if you buy the products which contain the natural ingredient, because that is keeping an industry alive which is in serious jeopardy. There aren't that many people who actually go out and look for a good pod."

When you find one, he says, there are all sorts of things you can do with it, including adding it to ground coffee. "Coffee with a hint of vanilla - it's amazing. But if you do buy the bottle of extract, look for real vanilla extract, which is going to cost you three or four times the price or more."

Avoid mass-produced vanilla ice cream. Ice-cream manufacturers proved the toughest nut for Ecott to crack: nobody would tell him any- thing about the way "vanilla" ice cream is made, but figures from the perfume industry suggest that vanilla absolute - that is, real vanilla - costs €4,000, against €16 for synthetic vanillin, so it doesn't take a rocket scientist to figure out what's probably in your favourite frozen product.

And don't rely on those cute little dark specks you find in "home-made vanilla" to tell you what's what in the ice-cream stakes. By-products of the vanilla extraction process that have no smell or taste at all, they're there purely for cosmetic purposes.

"Really, the only way the consumer can tell is by the price," says Ecott. "And check the labelling. In EU countries, if it says 'natural vanilla' or 'vanilla' without the word 'flavouring' attached, that will normally mean there is some natural vanilla in there."

Best of all, buy a couple of pods, open them up and just sniff. You'll never feel the same about plain old vanilla again.

Vanilla: Travels In Search Of The Luscious Substance, by Tim Ecott, is published by Michael Joseph, £16.99 in UK

Queen beans

• Vanilla vines can survive for hundreds of years in the wild, but natural specimens are now so rare that Mexican botanists have declared vanilla an endangered species

• Madagascar now produces more than half of the world's natural vanilla: about 1,200 of the 2,000 tonnes of beans available to importing countries each year

• The first known written reference to the vanilla orchid dates from 1552. It is described in the Libellus De Medicinalibus Indorum Herbis, which lay hidden in the Vatican library until the early 20th century

• Another famous vanilla document is tucked away at the Library of Congress, in Washington DC: Thomas Jefferson's own handwritten recipe for vanilla ice cream

• With annual sales of ice cream topping $20 billion (16 billion) in the US each year, vanilla is the most popular flavour, accounting for more than a third of the 1.25 billion individual ice-cream products sold annually. In the UK ice-cream eaters choose vanilla 90 per cent of the time

• Vanilla has been an unsung ingredient in designer perfumes, including Guerlain's Shalimar and Chanel's No 5, for years. More recently it has featured in Thierry Mugler's Angel, Yves Saint-Laurent's Opium, Dior's Dune and Lancome's Tresor