Malt is the biggest ingredient, and Pearl Barley is only $.49# at the grocer. I tried malting it- sure smelled malty, some sprouted too, but it got moldy too. Maybe hulls help prevent spoilage while seeds are laying on the ground waiting for spring? Then, since there are seldom hulls on the grains in the store, sparging would be a PITA. But, I suppose 10 pounds of rolled oats, mixed up with five gallons of water, a couple tea bags, boil for a while for sterility, cool, add an envelope of Fleischman's, let it settle in a secondary fermenter, you would have beer. Probably good enough for the ancient Pelopenesians anyhow...or high school kids that can't buy Bud yet....makes me wonder what the recipe for "beer in a bag" is....