The Extraction of Condensed Tannins in Red Wine Production

Over 25 wines were fermented on -20 scale using Cabernet Sauvignon grapes from four different vineyards in California. For each vineyard, a control fermentation was compared with treatments employing maceration treatments including oak extract addition, extended maceration, heat at the end, color enzyme addition, and rotary fermentation. All wines were analyzed for phenolic composition by several different assays. Many of the treatments had small or variable effects, but heat at the end appears to consistently increase phenolic levels. Wines from this and the previous years’ experiment will be offered for tasting at an event in the winter of 2001.