Gordon Biersch brews authentic German-style lagers and Hefeweizen from the finest ingredients, including two-row malted barley imported from Germany and Canada, and Bavarian hops and yeast from the Weihenstephan Yeast Bank in Freising, Germany. All Gordon Biersch beers are naturally carbonated during a six-week aging process, refrigerated door-to-door, and are brewed in accordance with Reinheitsgebot: the German Purity Law of 1516 requiring that beer be brewed with only malt, hops, water, and yeast, naturally carbonated, and created without the addition of any adjuncts or preservatives.