Article written by Ann Dumont, Céline Raynal, Françoise Raginel & Anne Ortiz-Julien

Research has shown how certain fermentation conditions, such as nutritional deficiencies, high initial levels of sugar, and the presence of inhibiting compounds, can lead to fermentation problems. Under oenological conditions, the main sugars fermentable by Saccharomyces cerevisiae are glucose and fructose. Both of these hexoses are generally present in musts in equivalent quantities, but the proportions may vary in some musts. S. cerevisiae prefers to consume glucose, which ex -plains why, when fermentations become stuck, the remaining sugar is mainly fructose. The frequency of stuck fermentations showing residual fructose raises the question of the ability of yeast to consume this hexose.  The kinetics of sugar utilization by S. cerevisiae during fermentation is largely driven by sugar transport, and glucose is typically consumed at a faster rate than fructose. In sluggish fermentations, the maximal rate of fermentation is reduced after most of the glucose is consumed, and fermentation can become stuck with a significant concentration of fructose remaining.

Please click on the button below for an in-depth explanation of this topic.