Date Available


Year of Publication


Degree Name

Master of Science in Biosystems and Agricultural Engineering (MSBiosyAgE)

Document Type

Master's Thesis




Biosystems and Agricultural Engineering

First Advisor

Dr. Czarena Crofcheck

Second Advisor

Dr. Tyler Barzee


Bourbon, or whiskey, production in Kentucky has been estimated to double within the next five years and an increase in the main by-product from bourbon distillation, stillage. Stillage is composed mostly of water along with the fermented grains after distillation. Stillage is expensive to dispose of and difficult to store due to the high biodegradability, posing a risk to the environment given the low pH and high chemical oxygen demand (COD). Anaerobic digestion has been identified as a potential solution for stillage valorization, but little research has been performed. Stillage from different mash bills has varying physicochemical properties, total solids (TS), volatile solids (VS), pH, and minerals and macronutrients. Distilleries employ varying distillation parameters and coupled with the heterogeneous makeup of the stillage from mash bills, is thought to have an impact on the biomethane potential of stillage. With a minimum methane production of 291.17±3.45 NmL/g VS and a maximum methane production of 419.19 ± 2.61 NmL/g VS out of 10 stillage samples from four distilleries with a food to microbe ratio of 1 g VS/ g VS and an organic loading rate (OLR) of 10 g VS/L, mash bill and distillation parameters were determined to impact stillage biomethane potential.

Digital Object Identifier (DOI)