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IVES 9 IVES Conference Series 9 Gambellara zoning: climate and soil effect on the aromatic fresh and dried grape composition and wine aroma

Gambellara zoning: climate and soil effect on the aromatic fresh and dried grape composition and wine aroma

Abstract

[English version below]

La région de production de la Gambellara et Recioto di Gambellara DOC (variété Garganega), tout en n’intéressant qu’une surface limitée, présente une certaine variabilité de milieu due à la morphologie du territoire (colline et plaine), à l’état actuel des sols et aux variations climatiques entre les différents sites. Pour les années 2001, 2002 ed 2003, après avoir divisé la région en sept parcelles, ont été analysées les caractéristiques compositives des raisins et la qualité organoleptique des vins. L’essai a été conduit aussi bien sur le raisin frais, destiné a fournir le vin Gambellara, que sur le raisin sec à partir duquel est produit le vin doux Recioto. Aussi bien les raisins frais que ceux déshydratés appartenaient à ces sept parcelles. Le contrôle des précurseurs aromatiques de variété obtenus par hydrolyse chimique et enzymatique, a confirmé le lien entre zones d’origine et teneurs en terpénoides, norisoprénoïdes et benzénoïdes dans le raisin frais, avec des concentrations plus élevées dans certaines zones par rapport à d’autres, obtenant ainsi une première caractérisation sur une base chimiques des différentes zones. La dégustation des vins obtenus à partir des raisins frais a confirmé, en grande partie, le lien entre la teneur en précurseurs aromatiques des raisins et les sensations olfactives, arrivant ainsi à une caractérisation organoleptique des vins et de leurs sites. L’analyse chimique des précurseurs aromatiques présents dans les raisins secs (cinq mois de passerillage) n’a pas donné la même échelle quantitative mise en évidence avec le raisin frais. Ceci nous amène à supposer que l’on doit faire une lecture plus attentive et plus approfondie des résultats. L’analyse organoleptique des vins secs (Recioto) a mis en évidence un lien quantitatif avec la teneur en précurseurs uniquement dans les cas présentant une plus grande richesse. Tout ceci confirme une différence aromatique certaine des raisins provenant des différentes zones, en fonction des facteurs de milieu étudiés. Avec le passerillage des raisins, le cadre aromatique s’enrichit pour certains composés (voir le néroli du groupe des terpènes et norisoprénoïdes par hydrolyse chimique), et il s’appauvrit pour d’autres (voir le linalol du groupe des terpènes). Le lien avec les facteurs climatiques et du sol devient maintenant moins certain, mais une différenciation persiste néanmoins en fonction des sites d’origine des raisins.

The first aim of the work has been to value the relationship between climate-soil characteristic and grape composition; then we studied the same correlation with the dried grape and in the end we took into consideration the aromatic quality of the wine. The trial has been done in the Gambellara area (North-east Italy). The area of production of the DOC Gambellara and Recioto di Gambellara wine (Garganega variety) even though it is a small area (1.000 ha), it has a notable environmental variability due to the landscape morphology (hill and plain), soil characteristics and the climatic differences between sites. For the three year period, 2001-2003, in the seven homogeneous zones in which the area was subdivided, we analysed the grape chemical characteristics (sugar, acidity, pH, aromatic compounds etc) and the organolectic quality of the wine. The trial and analysis were carried out using both fresh and, after a period of drying process, dried grapes, the first to obtain the Gambellara wine, and the second to obtain the Recioto sweet wine. The analysis of the varietal aromatic compounds on the fresh grape (obtained through enzymatic and acid hydrolysis) confirmed the close relationship between sub-zone origin (climate and soil water holding capacity) and quantity of terpenoids, norisoprenoids and benzenoids compounds. These quantity were different for different zones, directing us towards a first chemical characterisation of the zones. The tasting of wine obtained with fresh grape, in large part, confirmed the relationship between the quantity of aromatic compounds in the grape and olfactory sensations in the wine, obtaining in this way a good wine characterisation. The same chemical analysis seen before, were done on dried grapes (five month drying period) giving us a different scale of relative quantity between zones if compared with the fresh one. This leads us to suppose that other factors should be taken into consideration. Only those dried grapes richest in aromatic compounds give the most perfumed wines. All of this confirms a certain aromatic differentiation due to the origin of the grape and of the climatic condition of the zones. With the drying of the grape, the aromatic composition increases in certain compounds (e.g. nerol in the monoterpenes group and norisoprenoids) while losing others (e.g. linalool in the monoterpenes group). So for the dried grape and its wine, the effects of climatic and soil characteristics are less evident, but there remains a sure relationship with the zone of origin of the grape.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

D. Tomasi (1), G. Pascarella (1), D. Borsa (2), R. Minelli (3), P. Sivilotti (1)

(1) Istituto Sperimentale per la Viticoltura – Via XXVIII Aprile, 26, 31015 Conegliano (TV)
(2) Istituto Sperimentale per l’Enologia – Via Pietro Micca, 35 14100 Asti
(3) Soil expert

Contact the author

Keywords

Zoning, aromatic compounds, wine quality

Tags

IVES Conference Series | Terroir 2004

Citation

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