“Terroir” and grape and wine quality of native grape variety Istrian Malvasia

Viticulture and wine production have a historical tradition in Istria. First written document of vine cultivation in this area date since antiquity. The most wide spread vine variety in Istria is Istrian Malvasia (white variety), and it capture about 60% of total vineyard surface in Istria today. The Istrian Malvasia is a native grape variety in Istria, and it is one of the best varieties in a huge family of Malvasian varieties from Mediterranean basin. The Istrian Malvasia gives quality grapes for high quality wine production. Except the variety, on high quality of wine, a location of vineyard – «terroir» also has a very strong impact.
The objective of this research was to establish how different locations of vineyards influenced on grape and wine quality of Istrian Malvasia. Four specific locations have been chosen for this research. Those are: Pula – southern part of Istrian peninsula, with shallow red soils and low amount of rain in vegetation, Visnjan – western part of peninsula, with characteristics deep red soils and good physical and chemical properties, Motovun – central part of peninsula, with gray («flysch») soils, rich with clay, and bad physical and chemical properties and cold winter period and Buje – northwestern part of peninsula, with brown soils, good physical and chemical properties and good rain distribution through year. On all locations a growing form was Guyot – single or double branched.
Grapes and wine were analyzed from each location for harvest 2002. The content of acetate and ethyl esters, fatty acids and free monoterpenes was analyzed from wine extracts obtained by the solid phase extraction (SPE) method using C18 as a sorbent. SPE has already been applied for the analysis of aroma compounds from wine and grapes (Wada et al., 1997., Carballeira et al., 2001., López et al., 2002.). The content of higher alcohols was analyzed from wine distillates. All aromatic compounds were analyzed by gas chromatography. Wine from Buje location contains higher level of volatile esters, particularly iso-amyl acetate (average 2,04 mg/L), significantly higher then on the other locations. The wine from Buje location also contains significantly higher amount of free monoterpenes, especially linalool (average 27 µg/L) and geraniool (average 49 µg/L). The wine from Motovun location contains higher amount of higher alcohols, especially 2-phenyl ethanol (average 26,42 mg/L), significantly higher then on the other locations.
Summarized, all results show how not only the variety but also location of vineyard – «terroir» has a strong impact on the quality of grape and wine.