Terroir Traceability in Grapes, Musts and Gewürztraminer Wines from the South Tyrol Wine Region

Abstract

This study arose from the need to relate specific terroir aspects with experienced sensory properties of Gewürztraminer wines from Tramin (northern Italy). A multidisciplinary approach was used to investigate seven vineyards’ ecological characteristics, including geology and geographical features. A geopedological method using Vineyard Geological Identity (VGI) and Solar Radiation Identity (SRI) for topoclimatic classification, as well as multi-parameter measuring stations of air and soils, elicited analytical data for qualitative and quantitative terroir characterisations. Furthermore, wide-ranging and targeted oenological and chemical analyses were conducted on grapes, musts and wines to correlate their biochemical compositions with the measured terroir conditions. The study identified strong connections between vineyard geo-identity and wine mineral fingerprint, confirming mineral traceability of Rb/Sr ratio and of some minerals common to the local geology, such as Ba, Rb, Mn and Be. In particular, the most differing geo-mineral and physical soil conditions of two studied vineyards are apparent in the oenological components, flavours and aromas of their musts and finished wines. Amino acids, primary varietal aromas and polyphenols, thiol compounds with tropical scents, phenolic compounds with spicy notes and terpenic compounds, such as geraniol and citronellol, were related differently between fine-textured, more siliceous soils of glacial origin and coarser-textured, more dolomitic soils of local debris flow origin.