Combating high pH/high TA Missouri wines and its impact on non-volatile and sensory characteristics
Abstract
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Cation exchange treatment has been known to be an effective method to lower wine pH since at least the 1950s; however, it is often avoided due to concerns that it may have a deleterious impact on quality. To assess cation exchange impacts on non-volatile and sensory qualities, the polyphenolic, stability, and acidity parameters were quantified as well as descriptive sensory analysis was performed on four wine varieties reported to have an undesirably high pH and a high titratable acidity: Norton, Chambourcin, Syrah, and Valvin Muscat. Quantification revealed the success of resin-based cation exchange as a pH lowering technique with Norton 2013 as an example (pH 4.2 lowered to 3.5) and its minimal effects on the non-volatile components of these wine varietals. Analysis of variance statistical results for non-volatile and sensory data were varietal and vintage dependent. Evaluating cation exchange treatment when compared to the control, Valvin Muscat 2013 had 64% higher tartaric acid content and Norton 2014 had 10% higher anthocyanins as well as significantly lower scores for the Rotten eggs, Yeasty, and Bitter attributes. The 2014 Chambourcin, Norton, and Valvin Muscat cation exchange treated wines were significantly more Sour than the control. As it has been previously demonstrated, cation exchange was effective as a pH lowering technique and does not have a major impact on wine quality. However, more work is needed to better characterize Missouri wines in order to more confidently analyze the sensorial effects of cation exchange treatment.
Degree
M.S.
Thesis Department
Rights
Access is limited to the campuses of the University of Missouri.