But Gevo’s SAF provides an even more compelling case, because it is created in a cradle-to-cradle fashion. The ATJ-SPK is produced by using fermentation to convert sugars, starches, or hydrolyzed cellulose into alcohol (isobutanol or ethanol), which is subsequently processed into a mix of hydrocarbons. A wide range of feedstocks can be used—for example, in the case of corn—with the byproducts going directly back into the food chain. Spokesperson for Gevo, Andy Hawk, described it to Flying as a circular process. “The animal—the cow—needs the protein, and fuel needs the sugar” from the feedstock—and the high-protein animal feed created as a byproduct of fermentation even helps to reduce methane produced by the cows. Gevo’s first plant, in Luverne, Minnesota, is surrounded by the farms that provide the feedstock to the plant. Roughly 10 pounds of animal feed is produced per single gallon of SAF, according to Hawk.