Buying chocolate used to be a simple enough business, a small indulgence leaving us feeling ever so slightly naughty. These days it's more akin to a political statement, writes Richard Gillis

The chocolate industry is at the centre of several huge debates: obesity, Fairtrade and child labour among the cocoa growers used by major manufacturers. It's a habit we seem unable to kick, but there is evidence that our palate is changing and, with it, the way the business is run.

The market for block chocolate, which includes bars such as Cadbury Dairy Milk, was worth about £375 million (€538 million) over the past 12 months, rising by 8 per cent a year, according to AC Neilsen.

Buyers of confectionary are conservative, making new launches difficult. However, within the total market figure there are marked differences in growth rates and these delineate the territory over which the major brands are seeking to compete.

Taste is increasingly important, with low-fat options unable to penetrate the market, as witnessed by the failures of Flight and Mars Light. In our busy lives, treats seem to be valued more than ever.

Organic brands, such as Green & Black's, contain almost twice as much cocoa mass as the conventional Irish bar.

Dairy Milk takes up 40 per cent of the market despite a hellish year for Cadbury Trebor Bassett, in particular a salmonella scare that saw one million bars recalled at a cost of £30 million and 40 people affected by the outbreak. Cadbury saw a decline in its share of the chocolate market, and is taking some time to recover, according to food manufacturing analysts at ABN Amro.

Galaxy is in second place with a 12 per cent share, followed by Bourneville, Cadbury's dark-chocolate product, which is enjoying a renaissance, growing at 10 per cent per annum. The real growth in the market, however, comes at the premium end, with Lindt and Green & Black's posting double-digit growth figures.

"Britain and Ireland are ostensibly milk chocolate-eating countries," says Micah Carr-Hill, head of taste at Green & Black's, which was bought by Cadbury Schweppes in 2005.

The evidence suggests that this is changing, however. Green & Black's chocolate contains a far higher proportion of cocoa compared to its milky rivals: routinely double that of Cadbury Dairy Milk, for example.

The type of cocoa used also differs. About 97 per cent of chocolate is made using Forestero cocoa crops, whereas Green & Black's uses the Trinitario variety, which it claims offers a more complex, varied flavour and is sourced from the Dominican Republic.

The extra cost is passed on to the consumer, who seems prepared to pay a premium.

"The brand has been taken on by the foodies, who see chocolate as part of the broader gourmand experience," says Carr-Hill.

The rise of Green & Black's highlights the changing definition of luxury in today's consumer markets.

Data suggest that consumer expenditure on premium foods is predicted to increase by 27 per cent between 2003 and 2008. Upmarket chocolate is just one expression of this trend. But it is not as simple as that.

"Customers are using organic as a short cut to quality," says Carr-Hill. The concept of luxury is itself changing, with terms like "mass-tige" (prestige for the masses) being used to describe the growing aspirations of all.

Ostentatious spending on trophy brands is dismissed as bling. But brands such as Green & Black's capture the zeitgeist as a fusion of a high-cachet image with a strong environmental good news story.

Against this confusing backdrop, "Big Chocolate", the established multinationals, must continue to exert their economies of scale. The Irish market is dominated by Cadbury, Nestlé and Mars, just as Hershey, Nestlé and Mars rule in the US.

For most of the last century, these companies pulled off a delicate balancing act. Making chocolate was portrayed as a paternalistic exercise, and a highly profitable one.

Fry's, Rowntree and Cadbury have their roots in the Quaker movement. In the US, Milton Hershey, the "Henry Ford of chocolate", was from the pacifist Mennonites. The streets of Hershey, where the company is based, are named Cocoa and Chocolate Avenues. The respective companies traded profitably on this goodwill. But the reality is that chocolate is a mass-market commodity and competition is cutthroat.

The success of the niche chocolatiers such as Green & Black's, and the specialist Belgian and Swiss brands, is at odds with the industrialised British and American approach.

The focus for the industry centres on the level of cocoa used.

According to research by New Internationalist magazine, most countries, including the US and Russia, do not permit chocolate products to contain cheap vegetable fats, which reduce cocoa-butter content and often the dairy component in milk chocolate.

The major manufacturers want the EU to change its view of what defines chocolate, to be more in line with the British definition. Irish tastebuds have been trained to expect up to 5 per cent vegetable-oil content. Much of the rest of Europe prohibits vegetable fats.

The price of cocoa, the most expensive single component of chocolate, is on the rise. By reducing the amount of cocoa needed to make their bars, "Big Chocolate" firms are seeking to drive down the cost of manufacturing.

The Fairtrade movement says that, "for the well-being of the southern cocoa producers and the rights of the European Union consumer, it is imperative to harmonise the market at 0 per cent vegetable fats. The denomination 'chocolate' must be strictly reserved for cocoa-based products not containing vegetable fats other than cocoa butter."

It seems that, as our tastes in chocolate change, so the prospects for cocoa growers improve. Who knew that helping them could be so easy.