How Using Whole Clusters Impact Red Wine Quality
Aude Watrelot* and Andrew Horton
*Iowa State University, 536 Farm House Lane, 2567 Food Sciences
building, Ames, IA, 50011 (watrelot@iastate.edu)
Wines made from Marquette and Frontenac grapes are relatively low in tannins, the phenolic compounds responsible for astringency mouthfeel and ageability of red wines. In this study, the effect of adding whole clusters (WC) at 25 or 50% as a prefermentative technique was evaluated for basic wine chemistry and phenolic compounds content. Two grape cultivars, Marquette from Iowa and Minnesota and Frontenac, were processed following the same winemaking procedure in 2021. The basic chemistry, including organic acid and alcohol content, were evaluated throughout the process using HPLC-DAD/RID. Total iron-reactive phenolic compounds content and color intensity and hue were evaluated by UV-vis spectrophotometry and tannins content was quantified by HPLC-DAD/FLD. The percentage of alcohol in finished wines was not affected by the use of whole clusters, but was greater in Marquette wines from Minnesota and Frontenac wines than Marquette wines from Iowa. Addition of 50% WC led to significant increases in total phenolics and tannins content in all wines at bottling compared to control. However, the content of tannins was lowest in Marquette wines from Iowa and highest in Marquette wines from Minnesota. Aroma profile of wines made under the different conditions will be determined and the benefits of the WC addition on wine quality will be evaluated.
Funding Support: Midwest Grape and Wine Industry Institute
