Identification of the major drivers of 'phenolic' taste in ... - GWRDC

AWRI: Identification Of The Major Drivers Of ‘Phenolic’ Taste In White Wines
Formal Assessment
Samples were presented to tasters in 30 mL aliquots in 3-digit-coded, covered, ISO standard wine glasses
at 22–24°C, in isolated booths under amber lighting. The entire set of wines was presented in a
randomised order. The assessors were presented with four trays of four wines per tray. They were forced
to rest for 90 second between samples, and ten minutes between trays. During the ten minute break
assessors were requested to leave the booths. Samples were assessed over four days of formal sessions.
Forty-eight wines were assessed in triplicate, therefore 144 samples were presented in total.
The intensity of each attribute was rated using an unstructured 15 cm line scale from 0 to 10, with
indented anchor points of “low” and “high” placed at 10% and 90% respectively. Data was acquired using
FIZZ v 2.46 sensory data acquisition software (Biosystèmes, Couternon).
Panel performance was assessed using Fizz, Senstools (OP&P, The Netherlands) and PanelCheck
(Matforsk) software, and included analysis of variance for the effect of sample, judge and presentation
replicate and their interactions, degree of agreement with the panel mean and degree of discrimination
across samples (data not shown). All judges were found to be performing to an acceptable standard.
8.5 Results and Discussion
8.5.1 Standard Chemical Analyses
The experimental winemaking protocol used in both years produced uniform wines within fermentation
replicates and with analytical parameters that were within the ranges generally expected of commercial
white wines (Table 8-2). The wines were also technically sound, with less than 1.7 g/L residual sugar,
medium alcohol levels and low volatile acidity. In 2010 the wines made from different varieties were also
uniform with the exception of pH. Consequently, in 2011 the wines were carefully managed during
vinification and adjusted prior to bottling to achieve a pH value of 3.2 for all wines. Data for individual
wines are in Appendix B, Table B-5 and Table B-9.
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