TY - JOUR T1 - Addition Rate of Exogenous Tannin for Optimal Tannin Retention in Hybrid Red Wines JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. DO - 10.5344/ajev.2019.19022 SP - ajev.2019.19022 AU - Alex J. Fredrickson AU - David C. Manns AU - Anna Katharine Mansfield Y1 - 2019/10/30 UR - http://www.ajevonline.org/content/early/2019/10/28/ajev.2019.19022.abstract N2 - Winemakers often add exogenous products to increase tannin content in red hybrid wines, but the recommend dosage of 50-400 mg/L may not effectively increase the final concentration of condensed tannins. In 2013, wines were made from Maréchal Foch, Corot noir, and Cabernet franc to compare the retention of exogenous tannins in interspecific hybrids and Vitis vinifera. After analyzing 12 commercial tannin products for condensed tannin concentration via HPLC solid phase extraction-phloroglucinolysis, the product with the highest concentration (38%) was added at a rate of 400, 800, and 1200 mg/L after crush prior to yeast inoculation. One lot of each cultivar was also pressed off the skins immediately, fermented in the presence of 1600 mg/L of exogenous tannin, then back-blended post-fermentation with a control wine for a final theoretical concentration of 400 mg/L condensed tannin. At bottling, tannin concentrations in all treatments were higher than their respective controls. Tannin retention rates varied by cultivar, ranging from 19-24% in Maréchal Foch wines, 25-43% in Corot noir, and 34-48% in Cabernet franc. The back-blended wines had similar tannin retention rates to those with 400 mg/L additions in Corot noir and Cabernet franc, but higher tannin retention in Maréchal Foch (75 mg/L with a 400 mg/L addition and 93 mg/L in the back-blended wines). Though concentrations of condensed tannins were higher in all treatment wines, none exceeded 50% retention. This suggests that high concentration additions of exogenous tannin increase the condensed tannins in hybrid red wines, but retention rates vary by cultivar. ER -