Terroir 2016 banner
IVES 9 IVES Conference Series 9 Using a grape compositional model to predict harvest time and influence wine style

Using a grape compositional model to predict harvest time and influence wine style

Abstract

Linking wine composition to fruit composition is difficult due to the numerous biochemical pathways and substrate transformations that occur during fermentation. Grape composition regulates the production and final concentrations of most wine aroma compounds, as exemplified by methoxypyrazine and rotundone concentrations in wine being confidently predicted from the corresponding grape concentration. However, the final concentrations of many compounds in wines (aromatic and non-aromatic) are substantially dependent on the winemaking process.
The aim of this study was to better understand grape flavour evolution in relation to wine composition and subsequent wine style using sequential harvests (n=3). To achieve this goal, Shiraz was chosen as a model variety across two different climatic regions (warm-hot and cool-temperate) in New South Wales, Australia. The objective was not to compare the two regions but to assess the consistency of grape flavour evolution over the ripening period.

Irrespective of the region, a clear separation of samples was noted according to the harvest stage. Shiraz wines from the first harvest (H1) were associated with red fruit descriptors and higher acidity. Wines from the third harvest (H3) were correlated with dark fruit characters and a higher perception of alcohol. Higher concentrations of some higher alcohol acetates, dimethyl sulfide and lower concentrations of Z-3-hexenol, ethyl isobutyrate and ethyl leucate were measured in H3 wines.
Irrespective of the environment, this study demonstrated that in Shiraz, a common evolution of grape flavours exists, influencing the final wine sensory properties. Furthermore, during the late ripening stage, no direct nexus was observed between sugar concentration and grape and wine flavour evolution.

DOI:

Publication date: June 24, 2020

Issue: Terroir 2016

Type: Article

Authors

Alain DELOIRE (1), Katja ŠUKLJE (1), Guillaume ANTALICK (1), John BLACKMAN (1,2), 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

Contact the author

Keywords

fruit and wine composition, wine sensory profile, sequential harvest, regionality, climate, volatiles, multivariate data analyses

Tags

IVES Conference Series | Terroir 2016

Citation

Related articles…

Identification and quantification of molecular ellagitannins in cognac eaux-de-vie by a mass spectrometry method: barrel toasting and aging impact

Ellagitannins are the main oak wood phenolic compounds that contribute to wine and spirits organoleptic quality (color, astringency, bitterness)(1-3). Given the lack of knowledge regarding their composition and evolution in spirits, the objectives were to follow their extraction kinetic in Cognac “eaux-de-vie” matured in barrel representing different toasting and to observe their evolution and structural modifications during aging. METHODS: Eight different toasting levels were used for studying the impact of the toasting on ellagitannins composition. Two verticals (1978-2018) of “eaux-de-vie” samples coming from two terroirs were analyzed in order to observe ellagitannins evolution during aging. The above analyses were conducted using HPLC-Triple Quadrupole mass spectrometer (4) and the unknown compounds were identified by UPLC-Q-TOF, purified by preparative HPLC prior to 1D/2D-NMR analysis.

Analysis of the oenological potentials of different oak forests in Hungary

Like France, Hungary has many oak forests used for making barrels since many years. But if the differences between the woods of the North, the East and the South-West forests of France are well known, this is probably not the case of Hungarian forests. However taking into account the essential differences of climates and soils, differences must be significant and the general name “Hungarian oak” must not have any real meaning. We have studied precisely (determination of concentrations of volatile and non-volatile wood compounds, anatomical criteria, measurement of antioxidant capacity) of oaks collected from northeastern Hungary and others collected from the Danube valley in the northwest of the country.

Moscatel vine-shoot extracts as grapevine biostimulant to increase the varietal aroma of Airén wines

There is a growing interest in the exploitation of vine-shoots waste, since they are often left or burned. Sánchez-Gómez et al. [1] have shown that vines-shoots aqueous extracts have significant contents of bioactive compounds, among which several polyphenols and volatiles are highlighted. Recent studied had demonstrated that the chemical composition of vine-shoots is enhanced when vine-shoots are toasted
[2,3]. The application of vegetable products in the vineyards has led to significant changes towards a more “Sustainable Viticulture”. An innovative foliar application for Airén vine-shoot extracts have been carried out to the vineyard. It has been shown that they act as grape biostimulants, improving certain wine quality characteristics [4].

Adaptation to climate change by determining grapevine cultivar differences using temperature-based phenology models

Grapevine phenology is advancing with increased temperatures associated with climate change. This may result in higher fruit sugar concentrations at harvest and/or earlier compressed harvests and changes in the synchrony of sugar with other fruit metabolites. One adaptation strategy that growers may use to maintain typicity of wine style is to change cultivars. This approach may enable fruit

The adaptation and resilience of scions and rootstocks to water constraint

The ability of grapevine cultivars and rootstocks to cope with and adapt to recurring water constraints is the focus of this study. The contribution of intrinsic (epigenetic) and extrinsic (rootzone microbial community) factors to water stress resilience will be discussed. The study was conducted in a validated model vineyard where three scion cultivars (Pinotage, Shiraz, and Cabernet Sauvignon) on two rootstocks (Richter 110 and USVIT8-7) grow under recurring seasonal water constraint (and control) scenarios since planting (in 2020). Comprehensive profiling of the site, soil, atmospheric conditions, plants, and their physiological responses provide contextual data for the analyses conducted.