The use of different oak products during the fermentation and ageing of Chenin Blanc : sensory properties, perceived quality, and consumer preference

[摘要] ENGLISH ABSTRACT: Wooden barrels have been the preferred method for oak maturation for wines, but the use ofalternative oak products have increased options of oak maturation for winemakers, since newbarrels are expensive and have a limited lifetime. The main aim of this study was to investigatethe effect of different oak products used during fermentation and ageing on the sensory profile,degree of liking and perceived quality of Chenin blanc wine. The different wine treatmentsincluded an unoaked tank control wine, wines matured in 5th fill barrels, wines matured in newbarrels from three different cooperages, and wines matured in 5th fill barrels with stave insertsfrom two different cooperages. All of the treatments, except for the unoaked tank control, wereperformed in triplicate, rendering a total of 19 experimental wines.Sensory descriptive data were obtained with Pick-K attributes, using a trained and expert panelat three different intervals of wine maturation. These intervals included 4 months oakmaturation, 9 months oak maturation, and 9 months oak maturation with an additional 6 monthsbottle ageing. At the third maturation interval, an untargeted consumer study was alsoconducted using CATA questions to obtain descriptive and hedonic data. At this interval theperceived quality of the wines were also investigated using an expert panel. The expert panelreceived no formal training prior to any of the testing intervals. The trained panel were trained torecognise aromas from a list of 89 descriptors used by sensory scientists and industry expertsto describe Chenin blanc wines. The results obtained from the different panels at the differentageing intervals were compared.The biological repeatability of the different treatments were satisfactory from a cooperage pointof view. There were clear differences between the sensory profiles of the different winetreatments. Differences between the oak products from the different cooperages used withintreatments were less pronounced. There were significant differences in the degree of liking andperceived quality of the different products, but the degree of liking and perceived quality fordifferent products were comparable. The degree of liking and perceived quality of the 5th fillbarrels and new barrels were higher than the degree of liking and perceived quality of the stavetreatments. The mean degree of liking for the 5th fill barrels and new barrels were higher than forthe stave treatments. There were no significant difference between the degree of liking for theunoaked tank wine and the oaked treatments.The sensory descriptive data obtained from the trained, expert and consumer panel werecomparable in terms of panel consensus and configurational congruence. This validates thesuitability of CATA and its variant, Pick-K attributes, as rapid methods to elicit qualitativeinformation for the sensory profiling of wine.The results from this research made significant contributions towards method validation forCATA as rapid sensory method, and the descriptive and hedonic sensory results from thisresearch can be used by winemakers to both inform and justify the usage of specific oak products.

[发布机构] Stellenbosch University