Interaction Between Alcohol Concentration, Maturity, and Extended Maceration Treatment on Wine Phenolic Compounds
Juliana Pazos, Danielle Fox, Thomas Collins, and
James Harbertson*
*Washington State University, 2710 Crimson Way, Richland, WA,
99354-1671 (jfharbertson@wsu.edu)
The goal of this study was to evaluate the effect of alcohol concentration and harvest time on extended-maceration wines with their respective controls. Cabernet Sauvignon was harvested at three different times in 2019 from the Columbia Valley (at 22, 25, and 28 Brix) and soluble solids were adjusted to 20, 24, and 28 Brix for each harvest through chaptalization or saignée and water addition. An extended maceration (240 days of skin contact) was carried out for each harvest-soluble solids combination with their respective controls (10 days of skins contact). The 18 treatments were done in triplicate, resulting in the production of 54 wines. The Adams-Harbertson assay was used to measure anthocyanins, total phenolics, tannins, and polymeric pigments over 24 months. Anthocyanins significantly decreased between months eight (after pressing) and 12, while tannins and total phenolics significantly increased by month 24 (p < 0.05). By month 24, extended maceration significantly decreased anthocyanins and small polymeric pigments and increased tannins, total phenolics, and large polymeric pigments. Higher alcohol concentration significantly increased large polymeric pigment formation and late harvest increased anthocyanins (p < 0.05). Numerous interactions between harvest time, maceration length, and alcohol concentration were found, suggesting that these parameters have a significant influence on the phenolic composition of the wines. Significant interaction was found between harvest time and extended maceration for anthocyanins, total phenolics, and tannins, while an interaction between the maceration and alcohol treatments was significant for tannins and small polymeric pigments. Harvest time and alcohol concentration presented a significant interaction for large polymeric pigments. Focusing on the extended maceration wines, tannin concentrations were significantly greater for those wines with high alcohol, particularly when harvesting at 22 and 28 Brix.
Funding Support: Northwest Center Small Fruits Research
