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The Biochemistry of Wine Fermentations

The chapters encompassed under this heading address both the major (bio)chemical reactions that occur during alcoholic fermentation and their role in forming secondary odorants and other important compounds in wine (see the Introduction). The compounds discussed here are those that would be formed by fermentation of a media containing only basic nutrients, for example, sugars, amino acids, and essential vitamins and minerals – in other words, the compounds that are common to all alcoholic beverages. The chapters progress through the following:

• Glycolysis and Krebs cycle intermediates in the production of ethanol and organic acids
• Formation of co‐enzyme A thioesters and metabolism leading to fatty acids and their esters
• Amino acid metabolism and production of higher alcohols and their acetates
• Sulfur assimilation, and particularly its role in amino acid biosynthesis and in generating noxious hydrogen sulfide
• Lactic acid bacteria metabolism of key substrates (e.g., malic acid, citric acid, sugars) and the effects of spoilage bacteria.