Ethanol has gotten a bad name lately — deservedly so. Thanks largely to generous government subsidies, there has been a boom over the past few years in ethanol made from corn, which has succeeded in doing little more than driving up food prices. Biofuels made from food will never work, because food and the land on which food is grown are simply too valuable. But what if you could make biofuels from the parts of plants that we don't eat, like wood chips, inedible sugar cane or corn stalks? It's called cellulosic ethanol — so-named because cellulose, a sugar locked in the hard structure of plants, is the energy source — and Verenium is making it. The Georgia based company has built pilot plants that brew ethanol from sugarcane bagasse, and hopes within a few years to bring the cost of a gallon of cellulosic ethanol below the cost of gasoline. If they can do that, ethanol might recover its good name.