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

AWRI: Identification Of The Major Drivers Of ‘Phenolic’ Taste In White Wines
8 Sensory Characteristics of Different
Phenolic Composition Brought About
by Variations in Winemaking
8.1 Introduction
We aimed to produce a set of white wines that varied enough in phenolic composition to elicit
measurable differences in both taste and texture. A mix of both conventional and less practiced white
wine making techniques were used over two vintages. Hyperoxidation and skin contact were two
processes conducted pre-fermentation. Wines were also made from musts that were high in solids,
consisted of light and heavy press fractions, or included a small proportion of whole berries.
Most winemaking treatments were repeated over two years (2010 and 2011) using the same varieties,
and in the case of Riesling and Chardonnay the fruit was sourced from the same vineyards. Therefore,
in addition to providing wines of varying phenolic profile that could be used to identify those
responsible for ‘phenolic taste’, the work had the potential to provide preliminary data on the effect of
maceration and other aspects of juice handling on the phenolic profile and tastes/textures in white
wine. However, it should be noted that while fermentations were conducted in duplicate to ensure an
adequate set of sound wines with similar basic analysis, the winemaking treatments were not
replicated within each vintage.
8.2 Methods
8.2.1 Winemaking
Treatments
Musts were vinified over two vintages (2010 and 2011) from both low and high phenolic varieties to
create a set of wines with divergent phenolic composition. The treatments applied are given in Table
8-1.
Grape Sources
The Riesling and Chardonnay grapes were sourced from the Orlando St Helga vineyard (Eden Valley,
South Australia) and the Jacob’s Creek Lyndoch vineyard (Barossa Valley, South Australia)
respectively. Viognier grapes destined for commercial production were sourced from the Adelaide
Hills in 2010 and the Barossa Valley in 2011. All fruit was handpicked in order to avoid uncontrolled
maceration prior to winemaking, and chilled overnight.
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