The brewery will donate all of the ethanol-gasoline fuel blend for the convention's fleet of flex-fuel vehicles, the Rocky Mountain News reported.

Known as E85, the fuel is 85 percent ethanol and 15 percent gasoline. The ethanol in the blend is made from beer spillage or from beer that is rejected for quality reasons at the company's brewery in Golden, Colo.

The company began converting waste beer to ethanol in 1996. It produces about 3 million gallons of ethanol per year, the newspaper said.