German brewers say a five-century-old beer purity law deserves a spot on the UNESCO list for "intangible cultural heritage".

The law, called the 'Reinheitsgebot' in German, was introduced in Bavaria in 1516 and adopted nation-wide in 1906. It dictates that only water, malt, hops and yeast, and no flavourings or preservatives, may be used to make beer.

"If Germany is still regarded as the undisputed beer nation, that is due to the Reinheitsgebot," said Hans-Georg Eils, president of the German Brewers Federation.

Its acceptance to the world heritage list "would be for German brewers and maltsters a sign of appreciation and an incentive at the same time," Eils added.

The Federation calls the Reinheitsgebot the oldest still-valid food regulation in the world, and it is still cherished by many.

"Germans love their Reinheitsgebot," Berlin brewer Thorsten Schoppe told AFP, who added that some drinkers are sceptical at first when they hear the American-style craft beers he brews follow the law.

Brewers join German bakers, among other groups, calling for their crafts to be recognised by the United Nations' cultural organisation, UNESCO, as "intangible cultural heritage", alongside Argentina's tango, carpet weaving from southwest Iran and France's four-course gastronomic meal.

Germany became the 153rd state party to UNESCO's 2003 Convention for the Safeguarding of the Intangible Cultural Heritage this year. Its 16 federal states have collected proposals for possible inclusion on a national inventory, a prerequisite for later UNESCO listing.

The Reinheitsgebot was adopted in the Bavarian city of Ingolstadt by the Dukes Wilhelm IV and Ludwig X, and later spread to other areas under the provincial system.

It was originally developed to protect beer drinkers from cheap and sometimes hazardous ingredients.

Germany is Europe's biggest beer producer, though annual per-capita beer consumption has been declining in the country for years.