Terroir 2004 banner
IVES 9 IVES Conference Series 9 Role of Harvesting Time/Optimal Ripeness in Zone/Terroir Expression

Role of Harvesting Time/Optimal Ripeness in Zone/Terroir Expression

Abstract

[English version below]

La maturité optimale est définie en fonction du style de vin désiré, qui est fonction du marché. Le sol et le climat ont un effet sur la typicité des vins. Le niveau qualitatif des raisins et des vins, et le potentiel pour obtenir différents styles de vin est déterminé par l’association des caractéristiques naturel du terroir et les technologies mises en œuvres (i.e. les pratiques culturales à moyen et long terme). Les conditions de culture de la vigne doivent permettre une activité optimale des racines, des structures pérennes, de la canopée, des grappes et favoriser l’équilibre entre ces organes jusqu’à l’objectif final : des raisins de qualités différentes pour des styles de vin différents. La gestion et l’analyse des paramètres morphologiques et physiologiques de la canopée et des grappes, dans un environnement donné, est indispensable pour trouver les indicateurs qui peuvent être associés à une qualité de raisin et un style de vin. Ce point n’a pas été systématiquement étudié.
Dans cet article, un bref rappel de l’impact potentiel du terroir et des pratiques culturales court et long terme sera donné. La partie principale indiquera les résultats d’une collaboration de recherche faite sur Syrah/99R dans un vignoble de la région de Stellenbosch, Afrique du Sud. L’objectif a été de définir les paramètres de l’environnement, de la canopée et des grappes utilisables comme indicateurs pratiques et pertinents de la qualité du raisin en relation avec un style de vin. Les vignes sont conduites en Espalier (2,75m x 1,5m), les rangs sont orientés nord – sud, le vignoble est en pente orientée est. Une irrigation par micro aspersion est appliquée de la nouaison à la véraison. La hauteur de végétation est de 1,4 m, avec 2 hauteurs de fils de palissage. Les vignes sont palissées et écimées. Des prélèvements ont été réalisés tous les 15 jours depuis la nouaison jusqu’à la véraison. A partir de la véraison (14°Brix) des prélèvements de raisin ont été réalisés tous les 4 jours et jusqu’à sur-maturation, pour réaliser des mini vinifications. A chaque stade de prélèvement les paramètres du microclimat ont été mesurés. L’évolution végétative, reproductive et physiologique de la plante a été étudiée. Les fermentations ont été contrôlées pour chaque mini-vinifications. Les vins ont été analysés. Les similitudes et les variations dans l’évolution des paramètres et leurs ratio ont été analysées et interprétées.
Les résultats sont discutés en relation avec la performance de la canopée, l’allocation de carbone, les relations avec l’état hydrique de la vigne, le rendement, ainsi que le contenu en sucre, en acides organiques, en anthocyanes, en phénols et en tanins totaux des baies. L’ensemble est corrélé à la qualité des vins et à leurs composition. Les ratios des indicateurs sont testés pour déterminer la qualité optimale du raisin et la date de vendange en relation avec le style de vin. La pertinence et l’applicabilité des indicateurs sont discutées.

Optimal ripeness is defined according to the style of wine that is required. The latter is ultimately dictated by the market. Soil and climate may have a dictating effect on typical expression of wine. The level of grape and wine quality achieved and the potential for obtaining different styles of wine are determined by the integrated effect of the natural characteristics of the terroir and technological intervention (long and short term cultivation practices). The growth conditions that the grapevine is subjected to should allow optimal metabolic activity in roots, permanent structure, canopy and grapes and the potential for these organs to develop and support each other until the desired grape quality and style is reached. Monitoring of morphological and physiological parameters in the canopy and grapes, ultimately displaying the integrated effect of the growth environment, is critical in our quest for finding indicators that may be associated with a particular grape and wine style. This has not been systematically investigated.
Results of collaborative research done on a Shiraz/R99 vineyard in the Stellenbosch region, South Africa, with the purpose of defining environmental, canopy and grape parameters that may be suitable as eventual practical indicators for obtaining particular styles of grapes and wine, are presented. Vines were vertically trellised and spaced 2.75 x 1.5 m in north-south orientated rows on a Glenrosa soil and a west-facing slope. Microsprinkler-irrigation was applied at pea berry size and at vèraison stages. The 1.4 m canopies were shoot-positioned and topped. Fortnightly sampling was done from berry set up to two weeks post-véraison, after which harvesting for wine making was done approximately every four days. Microclimate, vegetative, reproductive and physiological parameters were investigated and changes during alcoholic fermentation monitored at each harvesting stage. Wines were made and analysed. Similarities in patterns as well as various ratios between the different parameters were investigated. Results are argued against canopy performance, carbon allocation, water relations, production level, and sugar, acidity, anthocyanin, phenolic and tannin contents of the grapes as well as wine quality and composition. Ratios for potential practical use in determining optimal grape quality, time of harvesting and expected wine style are discussed.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

J.J. Hunter (1), A. Pisciotta (2), C.G.Volschenk (1), E. Archer (3), V. Novello (4), E. Kraeva (5), A. Deloire (5), M. Nadal (6)

(1) ARC Infruitec-Nietvoorbij, Private Bag X5026, 7599 Stellenbosch, South Africa
(2) Dipartimento di Colture Arboree, Università degli Studi di Palermo, Viale delle Scienze 11, 90128 Palermo, Sicily, Italy
(3) Lusan Premium Wines, PO Box 104, 7599 Stellenbosch, South Africa
(4) Dipartimento di Colture Arboree, Via Leonardo da Vinci 44, I 10095 Grugliasco (TO), Italy
(5) Agro Montpellier, UMR 1083 « Sciences pour l’œnologie et la Viticulture », 2 place Viala, 34060 Montpellier cedex 1, France
(6) Departament de Bioquimica i Biotecnologia, Facultat d’Enologia de Tarragona, Ramón y Cajal 70, 43003 Tarragona, Spain

Contact the author

Keywords

Grapevine, Shiraz, physiology, grape composition, ripeness level, wine quality, wine style

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

High pressure homogenization of fermentation lees: acceleration of yeast autolysis and evolution of white wine during sur-lies ageing

AIM: High pressure technologies represent a promising alternative to thermal treatments for improving quality and safety of liquid foods.

Combined high-resolution chromatography techniques and sensory analysis as a support decision system tool for the oenologist

One of the main challenges in the wine industry is to understand how different wine processing techniques and practices can influence the overall quality of the final product.

EUGENOL AS QUALITY MARKER OF WINES AND SPIRITS FROM HYBRID VINES: IMPACT OF DIFFERENT WINEMAKING AND DISTILLATION PROCESSES

Eugenol, widely spread in various plants notably cloves, basil and bay, was identified too in wines from hybrid grapes without contact with oak wood. This aromatic molecule presents a strong spicy note of clove and also antifongic properties. Eugenol was described as an endogenous compound of Baco blanc, from the grapes to the spirits of Armagnac area. Moreover, this compound is a chemical marker of Baco blanc products quality.
Influences of harvest time and different winemaking processes (settling, use of enzymatic preparations, lees content and stock time before distillation) on Baco blanc wine eugenol contents were explored using a two-levels full factorial Design of Experiments (DoEs).

HYDROXYTYROSOL PRODUCTION BY DIFFERENT YEAST STRAINS: SACCHAROMYCES AND NON-SACCHAROMYCES AND THE RELATION WITH THE NITROGEN CONSUMPTION

Hydroxytyrosol (HT) is a phenolic compound with extensive bioactive properties. It is present in olives, olive oil and wines. Its occurrence in wines is partly due to yeast synthetise tyrosol from tyrosine by the Ehrlich pathway, which is subsequently hydroxylated to .
The aim of the present work is to study how different yeast strains can influence in the HT production and, how the different nitrogen consumption of each strain can interfere the production of bioactive compounds.

Asymmetrical flow field-flow fractionation with online multidetection is a viable tool to investigate colored red wine colloids

Despite its relevance for wine quality and stability, red wine colloids have not still been
sufficiently investigated, an occurrence due to the lack of suitable analytical techniques to study them as they are present in wine.