WINETECH Technical Yearbook 2021

TABLE 1. Thiol content (ng/L) of the Pinotage wines included in the experiment. Wines marketed as “coffee Pinotage” are underlined.

PT6

Wine code

3MHA

4MMP

3MH

4FMT

140

PT9

PT4

PT1

5.98

1.88

126.66

44.06

PT2

5.91

2.38

155.06

29.82

120

PT3

7.79

1.65

172.11

9.56

PT4

5.77

1.1

108.79

133.36

100

PT5

5.2

1.9

98.92

26.24

PT6

9.79

2.37

163.42

138

80

PT7

9.03

1.75

150.82

39.27

PT8

7.12

1.96

178.06

23.62

PT13

60

4FMT (ng/L)

PT1-R

PT9

6.82

1.26

161.54

136.58

PT7

PT1

PT10

4.86

1.31

149.25

6.03

40

PT2-R

PT2

PT11

5.87

1.07

82.15

5.92

PT8

PT5

PT12

5.54

1.2

119.3

25.96

PT12

20

PT3

PT13

4.62

1.38

151.52

56.15

PT11

PT10

0

0

10

20

30

40

50

60

70

80

90

100

Rating of coffee aroma (out of 100) FIGURE 1. Correlation between FMT concentrations (ng/L) and rating of coffee aroma. Underlined codes are for wines described as coffee/mocha/chocolate Pinotage on the bottle labels and tasting sheets. “-R” indicates a blind repeat.

RATING EXERCISE AND CORRELATION WITH THE CHEMISTRY RESULTS The rating task was considered of medium difficulty by the judges. Given that they had to rate only one attribute, the repeatability for the two blind replicates was excellent (PT1/PT1-R and PT2/PT2-R, figure 1). Some of the wines marketed as “coffee Pinotage” (underlined in figure 1) were evaluated quite low on the intensity scale for this attribute (<40 out of 100). Meanwhile, the three wines outstanding in their FMT content were also scored with the highest values in the sensory rating.

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