Hops are harvested all at once in the fall. The hops must be dried and stored at freezing temperatures to prevent spoilage. Beer takes about 0.5 to 1.0 pounds of hops per barrel (3 grams per liter). A moderate size craft brewery that makes 100,000 barrels of beer a year would need storage for as much as 50 tons of hops. In the form of pellets, 50 tons of hops would take up about 3500 cubic feet (100 cubic meters). This comes to 21 x 21 x 8 feet or 2.4 x 6.5 x 6.5 meters. Some breweries use hop extract, a concentrated liquid extracted from the hop plants. The volume of hop extract that would provide the same bittering as 50 tons of hop pellets would be about 200 cubic feet (6 cubic meters) or 1500 US gallons (5700 liters).