Not an expert, but Wikipedia seems to say all corn ethanol is made from edible grains, and that the alternative, cellulosic ethanol (made from inedible fibrous

Not an expert, but Wikipedia seems to say all corn ethanol is made from edible grains, and that the alternative, cellulosic ethanol (made from inedible fibrous parts) has not been commercialized. https://en.wikipedia.org/wiki/Corn_ethanol#Production_process https://en.wikipedia.org/wiki/Corn_ethanol#Production_proces... https://en.wikipedia.org/wiki/Cellulosic_ethanol https://en.wikipedia.org/wiki/Cellulosic_ethanol - "However, the much cheaper manufacturing of grain-based ethanol, along with the low price of oil in the 2010s, meant that cellulosic ethanol was not competitive with these established fuels. As a result, most of the new refineries were closed by the mid-2010s and many of the newly founded companies became insolvent. A few still exist, but are mainly used for demonstration or research purposes; as of 2021, none produces cellulosic ethanol at scale."