09 April 2013
This story has been flying around for the last 24 hours since it was reported at an ACS meeting in Germany, so I thought I’d bring you some details from NPR:
But researchers in Germany reported Sunday that they've found arsenic in hundreds of samples of beer, some at levels more than twice that allowed in drinking water.
When we checked in with experts about arsenic and the filtering process, which is also widely used in the wine industry, they weren't too surprised. That's because the filtering agent in question, diatomaceous earth, is a mined natural product that contains iron and other metals.
For centuries, the filter of choice for wine and beer has been diatomaceous earth. It's a beige powder made up of the skeletons of diatoms, tiny algae that lived in oceans many moons ago. Because the diatom fossils have lots of minute holes, they do a great job of filtering liquids — from swimming pool water to pricey champagne.
Arsenic in beer hit the news this week when Mehmet Coelhan, a researcher at the Weihenstephan research center at the Technical University of Munich, reported at a meeting of the American Chemical Society that many of the nearly 360 beers tested in Germany had trace amounts of arsenic.
A few were found to have more than 25 parts per billion of arsenic. That's twice the 10 parts per billion standard for drinking water in the United States.