The state of Kentucky produces 95% of the world’s bourbon, and all that bourbon leaves behind an enormous amount of waste grain, called stillage. Now, researchers at the University of Kentucky have developed a process to transform that stillage into electrodes. With the bourbon byproduct electrodes, they created supercapacitors that could store more nergy than similarly sized commercial devices. The researchers will present their results at the spring meeting of the American Chemical Society (ACS Spring 2026), held in Atlanta from March 22 to 26.

Turning bourbon stillage into carbon Josiel Barrios Cossio, a graduate student who will be presenting the work, first learned about the scale of American whiskey’s waste problem while working on a research traineeship to examine food, energy and water issues in Kentucky. “From the final volume of bourbon produced, you get 6 to 10 times that amount of stillage as waste,” says Barrios Cossio, “so it’s a big deal.”

This stillage is a sloppy mash that’s typically sold to farmers as livestock feed or a soil additive. But it is difficult to transport while wet, and it is expensive to dry.