Scientists Turn Bourbon Waste Into Supercapacitors With A 25x Energy Boost

by Aaron Leong — Wednesday, March 25, 2026, 11:42 AM EDT

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Scientists at the University of Kentucky have found a way to turn the soggy, grain-filled leftovers of bourbon production, a.k.a. stillage, into high-performance electrodes for supercapacitors, potentially turning Kentucky’s 95% share of the world’s bourbon market into a major player in the green energy grid.

No doubt then that one of Kentucky's bread-and-butter industries is the whiskey business. However, for every bottle of Pappy Van Winkle or Jim Beam you might enjoy, there are about 10 bottles' worth of a chunky, beige, oatmeal-like sludge left behind in the vats. Distilleries usually offload this stillage to local farmers as cow feed, but cows have their limits, and the sheer volume of waste is a logistical headache that requires expensive drying processes.

Enter the chemists Josiel Barrios Cossio and Marcelo Guzman who recently discovered that this waste is a goldmine of carbon. By stuffing the stillage into a 10-liter reactor and hitting it with intense heat and pressure (a technique known as hydrothermal carbonization), they transformed the sog into a fine black powder.

This powder was then treated in two different ways. Some of it was baked at 392° Fahrenheit to create hard carbon, a material where the carbon sheets are slightly messy and disorganized, making it the perfect storage medium for absorbing lithium ions. The rest was treated with potassium hydroxide and blasted at 1,472° to create activated carbon, which is packed with tiny pores that provide a massive surface area for holding an electrical charge.

bourbon1 — *Researchers converted stillage (left) into high-capacity electrodes for supercapacitors (right). (Credit: Josiel Barrios Cossio)*

When the team sandwiched these materials into coin-sized supercapacitors, the results were very positive. The activated carbon versions performed as well as high-end commercial models. However, the biggest surprise came when the team built hybrid devices using both the hard and activated carbons—they found that these bourbon batteries stored up to 25 times more energy per kilogram than traditional versions.

As they are, supercapacitors are prized for their ability to charge and discharge almost instantly, perfect for the regenerative braking in electric cars or stabilizing the power grid when the wind stops blowing. Manufacturing these devices relies on expensive or environmentally taxing carbon sources, so the idea of replacing or supplementing those with whiskey byproduct could be a big win.

While you won't be charging your Tesla by pouring a glass of Maker’s Mark into the glove box just yet, the University of Kentucky team is already looking toward commercialization. The team is scaling up the process and conducting life-cycle analyses to see how many gigawatts of power are currently sitting in Kentucky's distillery waste inventory.