Distilleries have been around since the dawn of time, including barleycorn (whiskey), maize (whiskey), potatoes (vodka), sugarcane (rum), and arcane brews distilled from beets, bread crumbs, and bamboo. The ethanol molecule cares not one wit about its particular provenance, so what is so special about a soil-depleting broom like switchgrass, when economically important sources have been around for millennia?

David C. Oshel
Cedar Rapids, Iowa

It’s true that just about any plant matter can be used to make ethanol. But because switchgrass is not a food source, high demand for switchgrass-based ethanol wouldn’t directly affect market prices for food commodities, as the demand for corn-based ethanol has done for corn prices. Also, switchgrass can be grown on land not suitable for food crops, and it requires relatively little energy to grow, which improves the net gain in energy from the ethanol produced. Using switchgrass leaves the other crops available for other purposes. —Patrick Barry