Influence of water status on sensory profiles of Ontario Riesling wines

The main objective of this study was to determine if remote sensing could help segregate vines at harvest and, if treated separately, lead to wines of different sensory properties. A commercial Riesling vineyard, Thirty Bench Winemakers, located in Beamsville (Ontario, Canada) was used for the study. The vineyard was delineated using global positioning systems (GPS) and 519 vines were geo-referenced. Six sub-blocks were delineated for study. The vineyard had initially been divided into three blocks by the winery for small-lot winemaking. Two of those blocks were each divided into sub-blocks based on vigor (low and high), which were determined by airborne imaging in 2005. Geographical information systems (GIS) software was used to delineate at least two water status sub-zones (based on leaf water potential) in each of the six sub-blocks. Grapes harvested in different. sub-zones were treated separately. Replicate wines were made from each sub-zone within all sub-blocks in 2007 and 2008. A trained panel of tasters developed a lexicon of descriptors to discriminate wines from the different sub-zones. Descriptive analysis of the wines showed that sub-blocks had a greater effect on the sensory profile of the wines than water status. Sub-blocks with high soil moisture and high leaf water potential (psi) produced wines with high peach/apricot aromas and honey flavor intensities, whereas those with low soil moisture and leaf 41 were more acidic with higher citrus and apple/pear flavor intensities. Remote sensing variables were highly correlated to most descriptors used, particularly citrus and apple/pear, which were very representative of these Riesling wines, and also highly correlated to berry monoterpene concentration. This suggests that the use of remote sensing could assist in making wines that are more representative of the particular cultivar used, which are also a reflection of a specific terroir, since soil moisture played a role in these results. (C) 2013 Elsevier Ltd. All rights reserved.