Winemaking variables and techniques are known to affect the phenolic composition of red wines. This review surveys the current literature on the impact of processing and fermentation parameters on the phenolic profile of the finished wines. Six winemaking variables and techniques have been reported to increase phenolic concentration: fermentation temperature, thermovinification, must freezing, saignée, pectolytic enzyme treatments, and extended maceration. In contrast, sulfur dioxide levels and cold-soak treatments have frequently been shown to have no or little lasting effect or to lead to a decrease in phenolic levels. Finally, carbonic maceration, yeast selection, and skin and juice mixing practices have produced variable results depending on the grape varieties studied. We recommend that you consult the full text of this article, which was originally published in the American Journal of Enology and Viticulture 56: 197-206.
