Understanding regionality and terroir in Australian Pinot noir

Aims: This study aimed to (1) characterise colour and phenolic profiles of commercial Australian Pinot noir wines, (2) understand regional drivers of sensory and volatile profiles of commercial Australian Pinot noir wines, and (3) generate a deeper understanding of where Australian Pinot noir wines profiles sit in an international context.

Methods and Results: A broad set of commercial wines was sourced from 10 Australian Pinot noir producing wine regions (n=102) from two vintages (2015 and 2016). The modified Somers method was used for preliminary colour and phenolic analysis of the wines. Noticeable colour and phenolic profile differences were observed amongst the regions. For example, wines from Southern Tasmania were found to have consistently higher anthocyanin levels. A sub-set of the broad group of Australian samples (n=80) was selected for grape-derived and fermentative volatile analysis (solid phase micro extraction coupled with gas chromatography–mass spectrometry) in addition to colour and phenolic analyses. Vintage was found to have a greater effect on aroma compounds than region. A narrower set of commercial wines (n=15) was sourced from 5 Australian Pinot noir producing wine regions for in-depth sensory (Pivot© Profile) and grape-derived and fermentative volatile analysis (solid phase micro extraction coupled with gas chromatography–mass spectrometry). The sensory assessment results showed that wines from the Mornington Peninsula, and to a lesser extent two from Northern Tasmania were associated with ‘red fruits’ aroma, while the majority of wines from Adelaide Hills, Southern Tasmania, and Yarra Valley, were associated with the attributes ‘floral’ and ‘oaky’ aroma.

Conclusions: Wine colour and phenolic analyses revealed demonstrable differences between Australian regions, and between the 2015 and 2016 vintages. Further investigation of volatile composition and sensory attributes of 2018 vintage wines showed regional sensory trends when it comes to Australia’s Pinot noir producing regions, with the Yarra Valley, Adelaide Hills and Mornington Peninsula showing similarities in their sensory profiles. However, from a sensory perspective Tasmanian Pinot noir tends to incorporate elements of all those regions into its sensory profiles, potentially reflecting the larger geographical size of the Tasmanian regions and greater terroir diversity in a single region.

Significance and Impact of the Study: The growing popularity of Pinot noir with Australian wine consumers underpins a need for better understanding the variety and its performance across varied terroirs. Many viticulturists and winemakers base agronomical and oenological practices on the colour and palate attributes of final wines. It is therefore important for the Australian wine industry to better understand the effect of regional compositional characteristics which potentially impact sensory attributes. These findings have the potential to support decision making for winemakers and viticulturists to achieve desired quality and stylistic outcomes and require further in-depth analysis of characteristics of the terroir. To the authors’ knowledge, this is the first study attempting to compare sensory and volatile profiles of Australian Pinot noir wines. Further studies including a greater number of samples and wine regions would provide more conclusive results, as would a comparative study using standardised winemaking protocols for fruit from a range of regions.