Sauvignon Blanc RSA: „Cool Climate“ Sauvignon Blanc: Wechselwirkung zwischen Hefepopulation, chemischer Zusammensetzung und Weinauthentizität

The aim of this research is to utilize a suite of microbial, chemical and stable isotope analysis methods to characterize Sauvignon Blanc wines derived from different geographical origins.

The objectives of the study are:
1.1 Monitor yeast dynamics in naturally fermented and inoculated wines using high throughput amplicon sequencing as well as culture-based microbial analysis
1.2 To analyse the chemical compositions of the finished wines using SPME-GC-MS/MS and infrared spectroscopy
1.3 To determine the traceability of the finished wines using stable isotope labelling
1.4 to exchange ideas and knowledge and to obtain further experience on methods for the characterization of typical Austrian and South African Sauvignon blanc wines from selected different geographical origin and terroir
1.5 using stable isotope analysis, infrared spectroscopy, GC/MS/MS and microbial community analysis
1.6 analysis of microbial community structures associated with selected wines and/or vineyards
1.7 to establish an optimized work-stream combining the data generated by the different methodologies
1.8 systematic study to establish the possibilities and limitations in differentiation of Austrian and South African Sauvignon blanc wines
1.9 to review and evaluate existing data and statistically interpret the results
1.10 to identify the strengths and weaknesses of the applied methods, and the improvement of interpretation by combination of methods and possible obstacles.

In 2017 the world wine production was estimated at 247 mhl, of which Austria contributed around 2.4 mhl and South Africa (SA) contributed 10.8 mhl. The two countries are ranked number 19 and 8, respectively with regard to wine production globally. The Austrian wine industry accounts for approximately 1.3% (around € 3.6 bn in 2014) of the National Gross Domestic Product (GDP) while in South Africa approximately 1.5% (WESGRO 2017, SAWIS 2016, SCHNABEL et al. 2016, STATISTIC AUSTRIA 2017). Austrian wines face strong competition from all over the world and Austria is constantly jostling against larger European producers. Similarly SA wines face strong competition from fellow Southern hemisphere countries such as Chile, Australia and New Zealand. Therefore, producing high quality wines with unique aroma and flavours that express “terroir” while maintaining cultivar typicity is necessary to ensure that these countries remain competitive in global markets.
Sauvignon Blanc is the third amongst the most cultivated white wine varieties in SA, however in some regions such as Stellenbosch and Elgin it is the first. Sauvignon Blanc wines from SA have achieved some significant national and international recognition. Similarly, in Austria, Sauvignon Blanc is the most important cultivar in regions such as Styria and has an important supporting character for local wine selling in all other regions. Over the years many endeavours have focused on modification of viticultural and oenological treatments to improve sensory and chemical characteristics of the wines from these regions, and enhance cultivar typicity (GREEN et al., 2011; MARAIS et al.,1999; MARAIS, 2001; SWIEGERS et al., 2009; PAVELESCU et al., 2015). However, this can also be achieved by using the diversity of species and ecosystems characteristic of vineyards (WANG et al., 2015; BOKULICH et al., 2014; SETATI et al., 2012, 2015; LOPANDIC et al., 2007,2008).