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Author ORCID Identifier
0009-0000-8191-8718
Date Available
2-13-2027
Year of Publication
2026
Document Type
Thesis
Degree Name
Master of Science (MS)
College
Agriculture, Food and Environment
Department/School/Program
Plant and Soil Sciences
Faculty
Luke Moe
Arthur Hunt
Abstract
The unique flavor profiles that distinguish bourbon brands are predominantly formed from variations in mash bills, yeast strains, and maturation practices. Yeast strains generate the foundation of the flavor profile during fermentation. However, fermentation is not a sterile process, as other microorganisms colonize and persist in distilleries despite industrial cleaning procedures. We hypothesize that the collective microbiome within the fermentation ecosystem contributes to the overall success and chemical makeup of the resulting spirit. To determine the impact of bacteria, we deliberately co-inoculated fermentations with bacterial species commonly found in distilleries: Levilactobacillus brevis (formerly Lactobacillus brevis), Enterococcus faecalis, Pediococcus pentosaceus, and Acetobacter pasteurianus.
We assessed the impact of single species inoculations at two inoculation titers (106 and 108 CFU/mL) on fermentation performance and volatile compound production. A small-scale, high-throughput fermentation strategy was developed and optimized for consistency across batches, enabling parallel studies between yeast-only fermentation and those with bacterial inocula. Analyses comparing co-inoculated samples against the control fermentations and against each other revealed significant differences in metabolite yields. Interaction effects were found between species and titer for some fermentation and volatile measurements. L. brevis and A. pasteurianus were found to differ the most from yeast-alone samples and had negative impacts on fermentation performance and volatile production. These results indicate that bacteria have a significant effect on fermentation and present opportunities for greater refinement of flavor within the alcoholic beverage industry.
Digital Object Identifier (DOI)
https://doi.org/10.13023/etd.2026.425
Archival?
Archival
Recommended Citation
Samuelson, Cooper R., "BACTERIAL CO-INOCULATION ALTERS THE BOURBON FERMENTATION VOLATILOME" (2026). University of Kentucky Master's Theses. 665.
https://uknowledge.uky.edu/gradschool_theses/665
