Terroir 2020 banner
IVES 9 IVES Conference Series 9 Regionality in Australian Shiraz: Sensory profiles of wines from six regions and their associations with chemical, geographical and climatic elements

Regionality in Australian Shiraz: Sensory profiles of wines from six regions and their associations with chemical, geographical and climatic elements

Abstract

Aim: Regional characters relating to Shiraz in Australia are not well documented. This study aimed to characterize the sensory, chemical and climate profiles of wines from various Australian Shiraz producing regions. 

Methods and Results: Sets of wines (22 to 28) from six prominent Australian Shiraz producing regions were assessed by groups of regional winemakers using a rapid sensory method called Pivot© Profile (PP) to obtain biplots of their sensory characteristics. Three or four samples from each region were selected using Agglomerative Hierarchical Clustering (AHC) analysis of the PP data resulting in a subset of twenty-two wines, which were then assessed using sensory descriptive analysis. A comprehensive chemical profile was also undertaken, including monoterpenes, norisoprenoids, low molecular weight sulphur compounds, oak volatiles, esters, and non-volatile compounds. Seventeen season-specific climate indices were also complied for each sample. Multivariate analyses (Principal Component Analysis and Partial Least-Squares Regression) showed that wines with stalky/cooked vegetal sensory attributes had higher cinnamate esters and dimethylsulfide, relating to a later budbreak and harvest day; wines with higher monoterpenes were associated with floral aroma; higher solar radiation was linked to higher tannin and colour density values, norisoprenoid and phenylethyl acetate concentrations and an association with dark fruit/dried fruit and tannin/colour attributes. 

Conclusions:

Distinctive sensory and chemical fingerprints exist for the specific regions studied, and the climatic profiles were strongly associated with key compounds influencing sensory differences. 

Significance and Impact of Study: Relating multiple site- and season-specific climate measures to chemical composition and characteristic sensory attributes of regional Australian Shiraz wines can help grape growers, winemakers and wine marketers better understand and promote the effect of place on their wines. 

DOI:

Publication date: March 17, 2021

Issue: Terroir 2020

Type: Video

Authors

Wes Pearson1,2*, Leigh Schmidtke1, I. Leigh Francis2, Sijing Li1, Andrew Hall1,3, B. Thomas Carr1,4, John Blackman1

1National Wine and Grape Industry Centre, Charles Sturt University, School of Agricultural and Wine Science, Locked Bag 588, Wagga Wagga, NSW 2678, Australia
2The Australian Wine Research Institute, PO Box 197, Glen Osmond, SA 5064, Australia
3Institute for Land, Water and Society, Charles Sturt University, PO Box 789, Albury, NSW 2640, Australia
4Carr Consulting, 1215 Washington Ave., Wilmette, Illinois, USA

Contact the author

Keywords

Wine regionality, Australian Shiraz, wine sensory profile, wine chemical profile, wine climate profile

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Effect of the commercial inoculum of arbuscular mycorrhiza in the establishment of a commercial vineyard of the cultivar “Manto negro

The favorable effect of symbiosis with arbuscular mycorrhizal fungi (AMF) has been known and studied since the 60s. Nowadays, many companies took the chance to start promoting and selling commercial inoculants of AMF, in order to be used as biofertilizers and encourage sustainable biological agriculture. However, the positive effect of these commercial biofertilizers on plant growth is not always demonstrated, especially under field conditions. In this study, we used a commercial inoculum on newly planted grapevines of a local cultivar grafted on a common rootstock R110. We followed the physiological status of vines, growth and productivity and functional biodiversity of soil bacteria during the first and second years of 20 inoculated with commercial inoculum bases on Rhizophagus irregularis and Funeliformis mosseaeAMF at field planting time and 20 non-inoculated control plants. All the parameters measured showed a neutral to negative effect on plant growth and production. The inoculated plants always presented lower values of photosynthesis, growth and grape production, although in some cases the differences did not reach statistical significance. On the contrary, the inoculation supposed an increase of the bacterial functional diversity, although the differences were not statistically significant either. Several studies show that the effect of inoculation with AMF is context-dependent. The non-favorable effects are probably due to inoculation ineffectiveness under complex field conditions and/or that, under certain conditions, AMF presence may be a parasitic association. This puts into question the effectiveness of its application in the field. Therefore, it is recommended to only resort to this type of biofertilizer when the cultivation conditions require it (e.g., very low previous microbial diversity, foreseeable stress due to drought, salinity, or lack of nutrients) and not as a general fertilization practice.

Experimental vinification of withered grapes of Vitis vinifera “Muscat of Alexandria”

The objective of the present work is to investigate wine produced from dehydrated grapes and vinified according to classical Roman manuals.

METHODS – Locally produced Muscat of Alexandria’s grapes were used for the sweet wine production, grown in the experimental vineyard of Instituto Superior de Agronomia (Lisbon, Portugal). The grapes were harvested manually slightly over-ripe and subjected to greenhouse drying. After 7-10 days dried grapes were transported to an experimental winery for various operations (e.g., grape weighing, sorting, crushing/destemming). Several maceration protocols were used comprising the addition of saltwater and white wine to whole bunches or destemmed grapes. Fermentation was conducted with the addition of commercial yeast. The standard physico-chemical parameters of wines were determined according to the OIV standards.

Grapevine drought tolerant ideotypes to adapt viticulture to climate change

Climate change is challenging the resilience of grapevine, one of the most important crops worldwide. Adapting viticulture to a hotter and drier future will require a multifaceted approach that must include new management strategies, increased irrigation efficiency, and the identification of more drought tolerant genotypes.

Subsurface irrigation: a means to reduce chemical and water inputs in vineyards

Grape growers around the world are seeking to reduce their reliance on herbicides. However, traditional alternatives to chemical weed control do not always integrate seamlessly into established vineyard operations. Employing nonchemical weed management often requires trellis alterations, purchasing or hiring new equipment, and depending on region, may significantly increase tractor passes required to reach desired level of weed control. Critical thinking and thoughtful strategies are necessary to minimize expenditures and maintain quality during the transition away from herbicides. In this trial, irrigation was installed underground in an effort to minimize water loss due to evaporation, better direct the water to the vines, and reduce weed growth in the difficult to control undervine area.

REGULATION OF CENTRAL METABOLISM IN THE LEAVES OF A GRAPE VINES VA- RIETAL COLLECTION ON A TEMPERATURE CLINE

Grape (Vitis vinifera) is one of the world’s oldest agricultural fruit crops, grown for wine, table grape, raisin, and other products. One of the factors that can cause a reduction in the grape growing area is temperature rise due to climate change. Elevated temperature causes changes in grapevine phenology and fruit chemical composition. Previous studies showed that grape varieties respond differently to a temperature shift of 1.5°C; few varieties had difficulties in the fruit development or could not reach the desired Brix level.