The Monitoring of Wine Faults in Georgian Wines

Abstract

In this study, the results from two different wine tastings were compared. The first one contains the results of wine evaluations provided by the tasting commission of the National Wine Agency of Georgia for the exportation of commercial wines in 2019. These wines are mainly produced by large wineries according to conventional winemaking methods (sulphiting, different types of filtration, conservation and stabilization by additives, etc.); 7039 samples were tasted. The second one contains the results of wine evaluations performed by the tasting commission of the Tbilisi New Wine Festival for small family producers, held in 2019. The wines are mainly produced according to methods of non-conventional or traditional winemaking; a totalof 575 samples were tasted. One of the main goals was to review the whole picture of the Georgian wine market in terms of wine faults. Tastings and evaluation of wines produced by family and big commercial wineries were not carried out simultaneously. The data collected were processed by statistical means. The tasting commission of the National Wine Agency of Georgia rejected 7% of the presented wines, because of oxidation, lack of typicity, and reductive wine faults. In the case of the festival wines, the rejection rate was 30%. The main reasons were mice flavor, oxidation, and elevated volatile acidity. The hypothesis for a correlation between individual wine faults and a specific wine category has been confirmed, e.g., a typical ageing (ATA) had the most considerable rate in white wines. Also, bacterial faults have been shown in the segment of wines of small producers that use fewer preservatives for wine production. The research showed that in contrast to the general opinion, for both - the industrial and the family wine segment, “mice flavour” dominated in white wines rather than in red ones. Interestingly, wines produced in qvevri vessels had less microbial faults than those made in other vessels. It has also been proven that some defects are correlated with wine colour regardless of the production method; other faults are correlated with the production method regardless of wine colour.