Sustainable Aviation Fuel (SAF) is poised for extraordinary growth as many companies accelerate efforts to help decarbonize air travel. This includes an enormous expansion of SAF capacity, along with dozens of major airlines committing to use the fuel.  Government policies are supporting the industry, including various state and federal tax credits for SAF in the U.S. and mandates to use the fuel in a growing number of European countries.  SAF can be produced from many feedstocks, including ethanol. Which pathways will rise to the top? Will SAF supply ever meet demand? Will SAF increase the costs of flying?