Enzymes are used to break down the carbohydrates into fermentable sugars. The fermentation takes place continuously over six cascading tanks, producing a 20-proof beer. The wash is then distilled into spirit using a five-step process. The water used in the vodka comes from a natural spring 150 meters (500 feet) below the blending facility in Cognac, which is lined with limestone, providing calcium-rich spring water. That water is then filtered to remove impurities. After the filtration the vodka is bottled in a plant dedicated solely to bottling Grey Goose. Grey Goose vodka is bottled with a replaceable cork rather than a screw-top cap.