Spanish researchers say they've developed a technique based on chemistry that is 99 percent accurate at revealing the country of origin of beer.

Measuring the content of iron, potassium, phosphates and polyphenols, researchers at the Spanish Foundation for Science and Technology correctly identified German, Spanish and Portuguese beers, a foundation release said Thursday.

"Beers can be differentiated from one another according to their country of origin by using parameters linked to raw materials, such as water (metals and negatively charged ions) and the type of hop (polyphenol content)," Jose Marcos Jurado, a chemist at the University of Seville, said.

"The differences can seem very subtle but the model is capable of detecting the relationship between these chemical descriptors and the country of origin of beers," he said.

Authenticity and geographical identification studies are "very important" for the food industry, researchers said, "given that they allow the differentiating characteristics of a product to be established.

"This can have an impact on their marketing."