Arsenic mystery solved

The mystery of arsenic in German beers has been solved, scientists announced at the 245th National Meeting & Exposition of the American Chemical Society.

Some German beers contain arsenic at levels higher than the World Health Organization limit for drinking water of 10 micrograms per litre.

“When the arsenic level in beer is higher than in the water used during brewing, this excess arsenic must come from other sources,” said Mehmet Coelhan from the Technische Universität in Munich.

“That was a mystery to us. As a consequence, we analysed all materials, including the malt and the hops used during brewing for the presence of arsenic.”

Coelhan’s team concluded that arsenic was released into the beer from diatomaceous earth, a filtering material known in Germany as kieselguhr, which is used to remove yeast, hops and other particles and clarify the beer.

Testing revealed that some kieselguhr samples release arsenic. “The resulting arsenic levels were only slightly elevated, and it is not likely that people would get sick from drinking beers made with this filtration method because of the arsenic,” said Coelhan.

In beer from more than six other countries, arsenic has been detected at higher levels than in German beer, according to a report. Coelhan says that breweries, wineries and other food processors that use kieselguhr should be aware that the substance can release arsenic. Substitutes for kieselguhr are available, Coelhan said, and simple measures like washing kieselguhr with water before use can remove the arsenic.