The Effect of Different Oak Products Used during Fermentation and Ageing on the Sensory Properties of a White Wine over Time

Abstract

The sensorial evaluation of Chenin blanc wine produced with different types of oak wood treatments over time has not been investigated before. The main aim of this study was to assess the sensory profile, using a trained panel, of a South African Chenin blanc wine fermented and matured in old barrels, three types of new oak barrels, two types of oak staves as well as a stainless steel tank over time, which has not been done before. Results indicate mainly separation between the stainless-steel tank/old barrel treatments from the stave and new barrel treatments, with separation between the latter two treatments also being found. More fruity descriptors were used in the stainless-steel tank and old barrel treatments, with oak-related descriptors being used in the stave and new barrel treatments. Separation between among the new barrel and stave treatments were also noted, which was still reflected during bottle maturation. These results indicate that winemakers need to take cognizance of the sensorial differences induced by barrel and stave maturation in white wines and how these evolve over time.

Keywords: Chenin blanc wine; oak wood; wine maturation.

Figure A1

Tasting sheet used by the panel during the different stages investigated.

Figure A2

Heat maps constructed based on the standardized residuals that were generated by the correspondence analyses of individual repeats obtained with the trained panel (n = 20) after 4 months of oak maturation. The more negative (i.e., the more “blue” on the heatmap) the residuals, the more indication that the correspondence (co-occurrence) between the items are less than what would be expected under the assumption of complete random occurrence. And vice versa, the more positive (i.e., the more red on the heatmap) the residuals, the more indication that the co-occurrence are more that expected under complete random occurrence. TC: Tank control, BC: Barrel control, B: New barrel treatments, S: Stave treatments.

Figure A3

Heat maps constructed based on the standardized residuals that were generated by the correspondence analyses of individual repeats obtained with the trained panel (n = 20) after 9 months of oak maturation. The more negative (i.e., the more “blue” on the heatmap) the residuals, the more indication that the correspondence (co-occurrence) between the items are less than what would be expected under the assumption of complete random occurrence. And vice versa, the more positive (i.e., the more red on the heatmap) the residuals, the more indication that the co-occurrence are more that expected under complete random occurrence. TC: Tank control, BC: Barrel control, B: New barrel treatments, S: Stave treatments.

Figure A4

Heat maps constructed based on the standardized residuals that were generated by the correspondence analyses of individual repeats obtained with the trained panel (n = 20) after 6 months of bottle ageing. The more negative (i.e., the more “blue” on the heatmap) the residuals, the more indication that the correspondence (co-occurrence) between the items are less than what would be expected under the assumption of complete random occurrence. And vice versa, the more positive (i.e., the more red on the heatmap) the residuals, the more indication that the co-occurrence are more that expected under complete random occurrence. TC: Tank control, BC: Barrel control, B: New barrel treatments, S: Stave treatments.

Figure 1

Correspondence analysis obtained with the trained panel (n = 20) after 4 months of oak maturation from Pick K data. Certain descriptors (boxed) have been moved to improve the readability of the plot. TC: tank control, BC: barrel control, B: new barrel treatments, S: stave treatments.

Figure 2

Correspondence analysis obtained with the trained panel (n = 20) after 9 months of oak maturation from Pick K data. Certain descriptors (boxed) have been moved to improve the readability of the plot. TC: tank control, BC: barrel control, B: new barrel treatments, S: stave treatments.

Figure 3

Correspondence analysis obtained with the trained panel (n = 20) after 9 months of oak maturation and 6 months bottle ageing from Pick K data. Certain descriptors (boxed) have been moved to improve the readability of the plot. TC: tank control, BC: barrel control, B: new barrel treatments, S: stave treatments.