Impact of Yeast-Handling Procedures on Beer Flavor Development During Fermentation. A. T. W. Pickerell, A. Hwang, and B. C. Axcell, The South African Breweries Ltd., Department of Research and Development, Box 782178, Sandton, 2146, Republic of South Africa. J. Am. Soc. Brew. Chem. 49:0087, 1991.

Low glycogen concentrations in pitching yeast resulted from unsatisfactory yeast-handling practices and were correlated with low viability, extended fermentation times, and high end-of-fermentation diacetyl levels. Adverse yeast-handling procedures also resulted in significantly higher end-of-fermentation concentrations of sulfur dioxide. Acetaldehyde profiles also were influenced by such procedures, and the uptake of group II and III amino acids was affected. This article discusses the relationship between pitching yeast glycogen and end-of-fermentation sulfur dioxide concentrations.

Keywords: Yeast quality, Glycogen, Fermentation, Sulfur dioxide, Acetaldehyde