Date of Award
5-2026
Document Type
Open Access Thesis
Degree Name
Master of Science (MS)
Department
Biology
First Advisor
Dr. Catherine Miller
Second Advisor
Dr. Lucille Benedict
Third Advisor
Dr. Rachel Larsen
Keywords
Biology
Abstract
Accurate assessment of yeast physiological health is essential for achieving consistent, efficient, and predictable beer fermentations. Although yeast vitality is more predictive of fermentation performance than viability alone, no universally adopted vitality assay currently exists in the brewing industry. This thesis investigates vitaltitration (VT) as a rapid, robust, and brewery-feasible method for quantifying yeast vitality and predicting fermentation performance. We hypothesize that VT provides a reliable measure of metabolic competence that correlates with fermentation kinetics across brewery-relevant yeast strains. To test this hypothesis, VT was evaluated alongside Acidification Power (AP) in structured serial-fermentation experiments in two phylogenetically distinct brewing yeasts: Saccharomyces cerevisiae (ale yeast) and kveik (a thermotolerant lineage of S. cerevisiae). By examining vitality dynamics and fermentation outcomes over multiple repitching cycles, we aim to determine whether VT can reliably predict fermentation performance and serve as a practical tool to better assess yeast health. Together, these experiments will provide the first multi-strain, serial-fermentation evaluation of VT and assess its potential as an industry-ready vitality assay for modern yeast management
Recommended Citation
White, Samantha MS, "Vitaltitration predicts fermentation performance of phylogenetically distinct Saccharomyces cerevisiae yeast strains" (2026). All Student Scholarship. 483.
https://digitalcommons.usm.maine.edu/etd/483
