GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Grape ripening and wine style: synchronized evolution of aromatic composition of shiraz wines from hot and temperate climates of Australia

Grape ripening and wine style: synchronized evolution of aromatic composition of shiraz wines from hot and temperate climates of Australia

Abstract

Context and purpose of the study ‐ Grape ripening is a process driven by the interactions between grapevine genotypes and environmental factors. Grape composition is largely responsible for the production and final concentrations of most wine aroma compounds even though many compounds in wines (aromatic and non‐aromatic) are substantially transformed during fermentation and wine ageing. The aim of this study was to investigate if a common pattern in grape/wine flavour plasticity related to ripening exists irrespective of a grape growing region. A further aim was to identify and highlight compounds present in Shiraz grapes and wines in which plasticity is directly related to grape ripening and is consistent over several vintages.

Material and methods ‐ Commercial vineyards of Shiraz were chosen in two Australian wine geographical indication (GI) regions: Griffith (warm to hot climate) and Orange (temperate to temperate‐warm climate). In these vineyards, own rooted vines were grown under drip irrigation, and trellised to a sprawling training system and in vertical shoot positioning for Orange. Sequential harvests were performed using berry sugar accumulation as a physiological indicator of grape maturity. At each harvest date, triplicates of 100 berries were collected and frozen in liquid nitrogen in the field for later chemical analyses. Approximately 60 kg of grape per replicate were randomly harvested at each harvest date and small scale vinifications carried out. Amino acids in grapes were analysed by high performance liquid chromatography (HPLC) coupled to fluorescence detector. Grape volatiles analyses were performed with gas chromatography coupled to mass detection (GC‐MS). Juice was analysed for set of parameters relating to the technical maturity of grapes (total soluble solids, titratable acidity and pH) and yeast assimilable nitrogen was measured. Wine aromatic compounds were quantitated by HS‐SPME‐GC‐MS. Descriptive sensory evaluation with predefined descriptors was conducted approximately six months after bottling.

Results ‐ Irrespective of the macro and meso climates, differences in both grape and wine chemical analyses and wine sensory description produced a clear separation of samples according to the harvest stage. Shiraz wines from the first harvest (H1) were associated with red fruit descriptors and higher perception of acidity. Wines from the third harvest (H3) were correlated with dark fruit characters and a higher alcohol. Later harvest dates resulted in higher concentrations of some amino acids in the Shiraz grapes, with higher alcohol acetates, ethyl esters (ethyl propanoate and ethyl butyrate) of short chain fatty acids and dimethyl sulphide in the wines. Conversely, concentrations of (Z)-3‐hexenol, ethyl isobutyrate, ethyl leucate and ethyl dihydrocinammate were lower in these wines compared to earlier harvest dates. Observed trends were significant and consistent across two vintages and two different GIs. From the plateau of berry sugar accumulation, no direct nexus was observed between berry sugar concentration and grape and wine flavour evolution. This study also demonstrated a common evolution of Shiraz grapes, influencing the chemical and sensory properties of the subsequent wine.

DOI:

Publication date: June 19, 2020

Issue: GiESCO 2019

Type: Article

Authors

Katja ŠUKLJE (1,3), Guillaume ANTALICK (1,4), Campbell MEEKS (1), John BLACKMAN (1,2), Alain DELOIRE (1,5), Leigh SCHMIDTKE (1,2)

(1) National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia
(2) School of Agricultural and Wine Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia
Present addresses: 3 Hacquetova 17, 1000 Ljubljana,
(4) Wine research centre, University of Nova Gorica, Glavni trg 8, 5271 Vipava, Slovenia
(5) Montpellier SupAgro‐IHEV‐BE, 2 Place Pierre Viala, 34060 Montpellier, France

Contact the author

Keywords

Grapevine, Australia, Shiraz, warm and temperate climates, sequential harvests, fruit and wine composition, sensory analyses

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

New insights on thiol precursors catabolism by yeast during wine fermentation: identification of the N-Acetyl-L-Cysteine conjugate

Understanding the catabolism of thiol precursors is essential for understanding the revelation of varietal thiols in wine. For many years, knowledge of these precursors has been limited to the S-conjugates of glutathione, cysteine (Cys3SH) and the dipeptides g-GluCys and CysGly, without being able to explain the full origin of 3-sulfanylhexan-1-ol (3SH) in wines

AOC valorization of terroir nuances at plot scale in Burgundy

In the highly competitive global wine market, Burgundy has a long-established reputation to maintain. The vine and wine sector in Burgundy is based on a five-level ranking of AOC (Appellation d’Origine Contrôlée) wines and of the plots where the grapes are grown.

Sensory evaluation of grape berries: predictive power for sensory properties of Sauvignon blanc, Riesling and Pinot noir wines

Sensory analysis of grape berries is a common tool to evaluate the degree of grape maturation and to make sound picking decisions.

Terroir analysis and its complexity

Terroir is not only a geographical site, but it is a more complex concept able to express the “collective knowledge of the interactions” between the environment and the vines mediated through human action and “providing distinctive characteristics” to the final product (OIV 2010). It is often treated and accepted as a “black box”, in which the relationships between wine and its origin have not been clearly explained. Nevertheless, it is well known that terroir expression is strongly dependent on the physical environment, and in particular on the interaction between soil-plant and atmosphere system, which influences the grapevine responses, grapes composition and wine quality. The Terroir studying and mapping are based on viticultural zoning procedures, obtained with different levels of know-how, at different spatial and temporal scales, empiricism and complexity in the description of involved bio-physical processes, and integrating or not the multidisciplinary nature of the terroir. The scientific understanding of the mechanisms ruling both the vineyard variability and the quality of grapes is one of the most important scientific focuses of terroir research. In fact, this know-how is crucial for supporting the analysis of climate change impacts on terroir resilience, identifying new promised lands for viticulture, and driving vineyard management toward a target oenological goal. In this contribution, an overview of the last findings in terroir studies and approaches will be shown with special attention to the terroir resilience analysis to climate change, facing the use and abuse of terroir concept and new technology able to support it and identifying the terroir zones.

Tasting soils in Pinot noir wines of the Willamette valley, Oregon

The conventional wisdom of vintners is that alkalinity, and thus less sour and more rounded taste, are enhanced in wine and grapes challenged by low-nutrient soils.