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.

Download the PDF

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…

Hierarchy of the interactions between physical and biological parameters intervening in the Pyrenean Gascon foothill vineyard

Un travail sur les A.O.C. du piémont pyrénéen occidental permet de construire une hiérarchie de paramètres climatiques, géo-pédologiques, morphologiques, de saisir leurs niveaux d’interaction et d’élaborer une méthodologie pour proposer un zonage

Read More

Gamma-ray spectrometry In Burgundy vineyard for high resolution soil mapping

Aim: A soil mapping methodology based on gamma-ray spectrometry and soil sampling has been applied for the first time in Burgundy. The purpose of this innovative high-resolution mapping is to delimit soil areas, to define elementary units of soil for terroir characterization and vineyard management. The added value of this integrated approach is a continuous geophysical mapping of the soil with an investigation depth of 60cm.

Read More

Temperature-based phenology modelling for the grapevine 

Historical phenology records have indicated that advances in key developmental stages such as budburst, flowering and veraison are linked to increasing temperature caused by climate change. Using phenological models the timing of grapevine development in response to temperature can be characterized and projected in response to future climate scenarios.
We explore the development and use of grapevine phenological models and highlight several applications of models to characterize the timing of key stages of development of varieties, within and between regions, and the result of projections under different climate change scenarios.

Read More

Impact of heating must before fermentation on Chardonnay wines

Prefermentation steps of white winemaking are very important for controlling the stability and the sensory attributes of wines. Usually musts are clarified by cold settling to prevent the start of the fermentation, before racking big lees and thus limiting the appearance of vegetable or reduction off flavour while favouring an aromatic expression with low turbidity. Besides, to reach the protein stability, some white wines further require a bentonite fining, sometimes associated with negative effects on the sensory quality. This study aims to know the impact of musts heating after pressing on a Chardonnay wine in northern conditions by comparison with a classic cold racking of the must.

Read More

Results of late-wurmian to present-day climatic-geological evolution on to spatial variability of pedologic-geological characters of the AOC Gaillac terroirs (Tarn, Midi-Pyrénées)

The AOC Gaillac area is divided into three main terroirs : « The left bank terraces », « The right bank coteaux » and
« The plateau Cordais ». This division is valid at a regional scale, but it suffers of a number of local-scale exceptions. This spatial variability of the pedologic-geologic characteristics at the plot scale has been derived mainly from the main late-Würmian solifluxion phase occurring at the transition between the peri-glacial climate and the Holocene temperate conditions (13,000-10,000 yrs BP).

Read More