Influence of maceration temperature and enzymes on the content of volatile phenols in Pinot noir wines

Yeasts of the Brettanomyces type are found in red wines and are responsible for the production of volatile phenols characterized by animal, leather, ink, horse stable or barnyard odors. Certain winemaking techniques that have been developed to improve the extraction of phenolic compounds indirectly favor the production of volatile phenols in wines that have been contaminated by Brettanomyces. Two techniques, heating at the end of the maceration and the use of enological enzymes, can potentially cause an excess production of volatile phenols. Compared with the classic temperature of the maceration without use of enzymes, one of these alternative techniques may triple the presence of volatile phenols, even more so when both techniques are administered on the same wine. Cinnamyl-esterase, a secondary activity seen in most enzymatic preparations produced by Aspergillus niger (pectinases), is the cause of this problem. The use of a purified enzyme without cinnamyl-esterase does not seem to induce an overproduction of volatile phenols. This property is already present in enzymes used in the vinification of white wines, and it is important to use these same purified enzymes for red wine production.