Beer is a significant source of dietary silicon, a key ingredient for increasing bone mineral density, and a moderate consumption of the golden suds could help fight deterioration of bone tissue known as osteoporosis, according to researchers at the Department of Food Science & Technology at the University of California, Davis. In fact, beer, they say in a study published in the Journal of the Science of Food and Agriculture, is a major contributor to silicon intake in the Western diet. Silicon is present in beer in the soluble form of orthosilicic acid or OSA.

“The factors in brewing that influence silicon levels in beer have not been extensively studied” said Charles Bamforth, lead author of the study. “We have examined a wide range of beer styles for their silicon content and have also studied the impact of raw materials and the brewing process on the quantities of silicon that enter wort and beer.”

The researchers studied commercial beer production to determine the relationship between beer production methods and the resulting silicon content. They examined a variety of raw material samples and found little change in the silicon content of barley during the malting process. The majority of the silicon in barley is in the husk, which is not affected greatly during malting.

The malts with the higher silicon contents are pale colored which have less heat stress during the malting process. The darker products, such as the chocolate, roasted barley and black malt, all have substantial roasting and much lower silicon contents than the other malts for reasons that are not yet known. The hop samples analyzed showed surprisingly high levels of silicon with as much as four times more silicon than is found in malt. However, hops are invariably used in a much smaller quantity than is grain. Highly hopped beers, however, would be expected to contain higher silicon levels. No silicon was picked up from silica hydrogel used to stabilize beer, even after a period of 24 hours and neither is there any pick up from diatomaceous earth filter aid.

The study also tested 100 commercial beers for silicon content and categorized the data according to beer style and source. The average silicon content of the beers sampled was 6.4 to 56.5 milligrams per liter.

“Beers containing high levels of malted barley and hops are richest in silicon,” says Bamforth. “Wheat contains less silicon than barley because it is the husk of the barley that is rich in this element. While most of the silicon remains in the husk during brewing, significant quantities of silicon nonetheless are extracted into wort and much of this survives into beer.”