The sensory characterisation of old-vine Chenin blanc wine : an exploratory study of the dimensions of quality

[摘要] ENGLISH ABSTRACT: Recently, there has been a lot of mention of the term 'old‐vine' in the media, the quality of the grapesthey produce and the type of sensory profile they exude. Chenin blanc in South Africa is, historically,one of the first wine grape varietals cultivated in South Africa and is not only the most widely plantedvariety, but many of these vineyards are far over 20 years old. The aim of this research was tocharacterise a representative set of old‐vine Chenin blanc wines and determine what could define itas a product style category, using descriptive sensory analysis (DA). There is no formally defined agefor an old‐vine, therefore, for the purpose of this study all old‐vine wines evaluated were 40‐years andolder.In this study the focus was shifted from mainly concentrating on the aroma characteristics of thewines, as had been the case in previous Chenin blanc research, to include other aspects that are alsoassociated with the intrinsic quality of wine. These aspects were referred to as 'in‐mouth sensations'and were selected by a focus group of industry professionals and expert panellists. The in‐mouthsensations included body, heat, acidity, balance, complexity, concentration, integration and length.This was the first time the DA panel had to evaluate these concepts in wine, therefore, extensive paneltraining was needed and a framework was created to aid in the analysis of these concepts. Due to thedifficulty of the analysis, and the limitations of DA, the wines were analysed in two smaller sets, witha maximum of 10 wines per set.In general, information on the vines and the production practices of the wines investigated in thisstudy, is fragmented and scarce. Qualitative research was, therefore, used by means of aquestionnaire to give context on how the vineyards of the wines investigated in this study aremanaged and the winemaking techniques used to produce these wines.The old‐vine Chenin blanc wines were not all characterised by distinctive aroma attributes, but eliciteda subtle array of aromas. The aroma profile of these wines was, therefore, described as complex. Thewines had prominent, but different in‐mouth properties within the set. The sensory data also showedthat body, balance, concentration, complexity and integration were all positively correlated and thatacidity was negatively correlated to those concepts. The correlation between the in‐mouth sensationsand physicochemical parameters was investigated as a secondary objective. Body had a strong positivecorrelation to ethanol, dry extract and reducing sugars. The results showed that the physicochemicalparameters correlated with body, were also positively correlated to balance, concentration,complexity and integration. Therefore, the physicochemical composition of the old‐vine Chenin blancwines had a large impact on the perception of in‐mouth sensations.The results obtained on in‐mouth sensations with DA, for the second set which included 10 wines,were compared to a reference based rapid method, polarised sensory positioning (PSP). PSP allowedfor the analysis of a larger sample set (15 wines) and the results were similar compared to that of DA.This was the first application of this rapid method to wine.Therefore, this study provided insight into the sensory profile of the old‐vines wines of South Africa'smost important cultivar, Chenin blanc, and developed a framework for analysing in‐mouth sensationsin wines, that could be applied in future research. The study also proved that PSP could successfullybe applied to wine, which would allow for the analysis of more comprehensive sample sets. Lastly, thequalitative information gathered helped to identify opportunities for prospective research. Overall,research on the old‐vine Chenin blanc wines helps aid in the awareness of the quality and importanceof these vineyards.

[发布机构] Stellenbosch University