L’utilisation de levures sélectionnées est généralement considérée comme le moyen d’éviter les problèmes fermentaires. Néanmoins de nombreux viticulteurs pensent que ces levures sont à l’origine d’une standardisation des vins et militent pour le respect d’une flore indigène (Bourguignon, 1992).
Syrah is a grape with weak aromatic expression. This atypical grape variety as a fruit allows the production of wines of great reputation for which the aromatic particularity plays an important role. The varietal aroma consists of volatile substances directly perceptible by the olfactory mucosa and of aroma precursors, of which the glycosides constitute an important class.
A set of Syrah plots covering a wide range of terroirs distributed in the vineyards of the Rhone Valley and the Mediterranean South is examined through their oenological and sensory characteristics. The multidimensional analysis of data leads to the following groupings: (1) A group of unstructured wines with a simple aromatic profile dominated by fruity-floral notes; they come from plots where the ripening conditions have been disturbed by unfavorable climatic conditions, or an excess harvest.
The historian starts from a scientific, rigorous and recent definition of the wine-growing region. “A viticultural terroir is made up of several homogeneous units: geological and pedological elements (texture,
grain size, thickness, mineralogical nature, chemical components), geomorphological (altitude, slope, exposure), climatological (rainfall, temperature, insolation)”. Absent from this definition, the man is fortunately reintroduced a little further. By associating viticulture and winemaking, it forms a “couple” with the terroir and this couple.
It is not easy at first sight to give an exhaustive definition of the notion of terroir as it can be simplified or complicated at will. Thus the vagueness that surrounds this concept leaves the door open to various interpretations of the terroir. These tend towards a questionable level of objectivity because the fields they explore are not sufficient to explain the notion on their own, constituting only part of a whole.
The research carried out by the URVV of the INRA center in Angers aims to develop a methodology for the integrated characterization of the natural factors of viticultural terroirs, representative of the operating conditions of the vine and the sensory differences of the wines. In this context, the concept of Basic Terroir Unit (UTB) has been developed. The UTB represents a viticultural surface of variable geographical extension, defined as the association in a given place of a geological, pedological and landscape component, Morlat (1989), Riou et al. (1995).
The AOC Saint-Emilion, one of the most prestigious in Bordeaux, is located on the right bank of the Dordogne upstream from Libourne. The vineyard is planted on Tertiary (Oligocene) and Quaternary geological formations, on which very varied soils have developed. Numerous studies have taken account of this heterogeneity and made it possible to better understand the functioning and viticultural potential of these soils (Duteau et al. 1981, Van Leeuwen, 1991).
The Pomerol vineyard, located 35 km east of Bordeaux, covers around 800 ha on the left bank of the Isle. There is a system of fluvial terraces with more or less coarse gravel and pebble spreading, resting on a Tertiary substratum ranging from the Middle to Upper Eocene to the Lower Oligocene (Dubreuilh, 1993). This interweaving of terraces of varying thickness results in a brutal superposition of differentiated materials which give rise to various types of soil. Several site studies in this sector of the Libounais show significant morphological and analytical differences from one point to another (Guilloux et al ., 1978; Duteau, 1982; Van Leeuwen et al.., 1989). The distribution of the soils of the Pomerol vineyard was studied and resulted in a cartography at 1/25000th (Merouge, 1995).
The viticulture of the Douro Delimited Region, one of the heirs of ancestral viticulture, traditionally empirical and of quality, while integrating modernity and contemporary tools, respects and has always present the principles on which it was developed.
The Appellation d'Origine Contrôlée of Bandol covers an area of 1365 ha, 83% of which are planted with vines, the annual production being around 40,000 hl. Among the wines produced, there are mainly reds which assert themselves over time, but also rosés characterized by their pale colour, generally orange; the whites represent a small part of the production. The main grape variety of this AOC is Mouvèdre, of Spanish origin, which is also found in Provence and Languedoc.
A partir des recherches conduites sur la caractérisation des terroirs viticoles par des chercheurs de l’Unité de Recherches Vigne et Vin (1, 2, 3, 4, 5) du Centre INRA d’Angers, Terre des Sciences, le Centre de Culture Scientifique et Technique d’Angers (CCSTA) a mis au point un parcours de découverte d’une journée dans le vignoble angevin avec une approche pluridisciplinaire.
A study of the influence of environmental factors on the ripening of grapes under the conditions of Alsace is carried out. Emphasis is placed on the analysis of the mesoclimate and pedoclimate. The experiment is conducted on a network of plots of gewurztraminer grafted on SO4. The production conditions are standardized throughout the device.
On peut être surpris de l’existence d’un vignoble de vins liquoreux, le vignoble des Coteaux du Layon, dans une zone septentrionale à la limite Nord de la culture de qualité de la vigne et ce d’autant plus que le cépage de ce vignoble, le Chenin ou Pineau de la Loire, est un cépage semi tardif. La première explication est à rechercher au niveau des facteurs naturels (données climatiques et géopédologiques) permettant la réalisation de ce type de produit. Il est nécessaire de souligner ici l’importance de chaque paramètre du terroir pris dans im sens large (géopédologique et climatique) et que toute variation de l’un d’entre eux, même non perceptible en première analyse à l’homme, peut avoir des incidences déterminantes sur la qualité des vins.
The maturation patterns process has been very studied. In particular the modelization of the sugars and titratable acidity during the ripening period was an important approach, in particular for the prediction of harvest date (Barillere et al., 1988; Jourion et al.,1987; Maujean et al., 1983; Scienza, 1989). In Oltrepò Pavese, the widest viticultural district of Lombardy – Northern Italy – (about 15000 hectares), grape maturation trends shows high variability, due to the large variation in environmental characteristics of vineyards (altitude, exposure, soil type, mesoclimate) and to “cultivar x environment” interaction.
Different terroirs have been identified in Bolgheri area (a viticultural appellation in the Tirrenian coast of Tuscany) by the aid of pedological, landscape and agronomic observations in 1993. Numerous preliminary observations suggested that wines obtained from these different terroirs were unique.