Date of Award
2006
Degree Type
Thesis
Degree Name
Master of Engineering Science
Program
Chemical and Biochemical Engineering
Supervisor
Dr. Argyrios Margaritis
Abstract
Employing very-high-gravity (VHG) wort for batch beer production is industrially appealing due to the potential for increased process efficiency and cost-savings. However, this practice has not been extensively commercialized as the stressful conditions thus created can lead to severe effects on yeast health and fermentation performance. The strategy employed in this investigation to mitigate yeast stress and optimize VHG fermentation performance involved simultaneous manipulation of process parameters (i.e. oxygen supply, inoculum size and temperature profile) and wort nutritional factors (e.g. level and source of assimilable nitrogen). This resulted in a 33% reduction in the time to achieve end of fermentation targets (i.e. attenuation and diacetyl), compared to fermentations conducted under control conditions. Furthermore, the improved fermentation profile was consistent over three serial fermentation cycles and no significant impact was observed on key flavour metabolites. The multi-parameter solution presented to alleviate yeast stress under VHG conditions could be easily implemented in an industrial brewery setting.
Recommended Citation
Jones, Heather Lynn, "A Multi-Parameter Investigation for Optimization of Very-High-Gravity Batch Beer Fermentation by Saccharomyces cerevisiae" (2006). Digitized Theses. 4632.
https://ir.lib.uwo.ca/digitizedtheses/4632