An examination of substrate and product kinetics during brewing fermentations

Andrew J. MacIntosh*, Maria Josey, Robert Alexander Speers

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Brewers monitor density attenuation during fermentation to detect process deviations and to approximate other fermentation parameters. The most common relationship used to monitor fermentations is Balling's formula. It has been argued by many researchers that this relationship no longer adequately describes fermentation within modern breweries. This study monitored conversion of sugars into fermentation products in an attempt to assess the accuracy of historical and current theories. Experiments were conducted at laboratory scale using a standard assay with both sugar consumption and major product generation assessed at a high sampling frequency. The results were used to assess the accuracy of product formation models (such as Balling's) and to examine how product and substrate ratios changed over the fermentation. It was found that the majority of yeast and glycerol formation occurred within the first half of fermentation. Additionally, yeast cells held in suspension were fairly consistent in sugar consumption rate throughout the fermentation. Finally, it was found that while the consumption of each brewing sugar was highly ordered, there was a great deal of overlap between sugar utilization during the fermentation. This information will hopefully allow brewers to make informed decisions and to enable the use of accurate estimations of alcohol, yeast, and sugar contents for their final product.

Original languageEnglish
Pages (from-to)250-257
Number of pages8
JournalJournal of the American Society of Brewing Chemists
Issue number4
Publication statusPublished - 2016


  • Carbon balance
  • CO
  • Fermentation
  • Glucose
  • Maltose
  • Modeling
  • Sugar consumption
  • Yeast

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Applied Microbiology and Biotechnology


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