Date of Award
Master of Science
John P. Munafo
Mark Morgan, Tao Wu, Curtis Luckett
The processing step that makes Tennessee whiskey unique from bourbon is known as the Lincoln County Process (LCP). It is performed by filtering fresh whiskey distillate through a bed of maple charcoal. A model LCP system was developed, and the aroma of whiskey before and after LCP treatment was characterized. Sensory comparison of the two distillates was performed by olfactory profile analysis. Odorants in the two distillates were identified by comparative aroma extract dilution analysis (cAEDA). The odorants were then quantitated by stable isotope dilution assays (SIDA), and odor activity values (OAVs) were calculated based on the odor threshold of each odorant in an ethanol and water matrix as well as the concentration of each odorant. The LCP treatment was found to cause a decrease in the malty, rancid, fatty, and popcorn character of the distillate sample. A total of forty-nine odorants were identified in the distillate samples, nine of which are being reported for the first time in whiskey distillate. Twenty-nine odorants were quantified in the distillate samples, and all decreased between 13 and >99% as a result of LCP treatment. Four odorants, namely, (2E,4E)-nona-2,4-dienal (fatty), 3- methylbutanoic acid (sweaty, rancid), and corn-derived 2′-aminoacetophenone (foxy), and 2-acetlyl-1-pyrroline (popcorn) dropped below their detection thresholds (OAV < 1) as a result of LCP treatment. The LCP treatment decreased lipid-derived aldehydes, organic acids, and corn-derived odorants by between 55 and >99%. The work presented here lays the groundwork for more comprehensive investigations into the process that makes Tennessee Whiskey unique from bourbon and provides an analytical toolkit to aid distillers in optimizing the flavor profile of their products.
Kerley, Trenton, "Characterization of Changes in Whiskey Odorants by the Lincoln County Process. " Master's Thesis, University of Tennessee, 2019.