Impact of Winemaking Techniques on Classical Enological Parameters and Rotundone in Red Wine at the Laboratory Scale

The impact of fermentation variables (time and temperature of maceration, yeast species, addition of pectolytic enzymes) and winemaking techniques (cold soak, thermovinification, carbonic maceration, and rosé vinification) on rotundone and classical enological parameters was investigated in triplicate in red wine made from Duras at the laboratory scale. Rotundone was poorly correlated to anthocyanins and to total phenolic index, some variables reflecting the extraction of skin compounds, which suggests that the solubility of rotundone or its ability to bind to other materials may differ from anthocyanins and most of the grape proanthocyanidins. Compared with control wine, wines made from a rosé and a thermovinification treatment differed largely in their enological parameters. These two treatments involving a preferment removal of skins resulted in the lowest wine rotundone concentrations of ~20% and 13%, respectively. The other treatments had a weak impact on the studied parameters, and none of them, including the use of macerating enzymes and the increase in temperature or time of maceration, resulted in enhanced rotundone concentrations. Semicarbonic maceration, fermentation with Saccharomyces uvarum, or longer skin contact during postfermentation maceration resulted in wine with a significant decrease of ~20% in rotundone concentration, indicating practical opportunities for reducing pepper aroma in wine.