Aikaterini Tzamourani, Marion Favier, Ioannis Paraskevopoulos, and Maria Dimopoulou*
*Department of Wine, Vine and Beverage Sciences, School of Food Science, University of West Attica, 28 Ag. Spyridonos St., 12243 Egaleo, Greece, 12243, Greece (mdimopoulou@uniwa.gr)

Assyrtiko is a rare ancient grape variety of Greece, known for production of Protected Designation of Origin Santorini white wines. Besides the famous character of the volcanic terroir, Assyrtiko of Santorini is also marked by low pH and sharp acidity. With climate change, this acid typicity tends to be under-expressed and ways to reinforce acidity in warmer vintages need to be sought. The aim of this study was to apply a new inoculation procedure that modulates the fermentation process by maintaining the unique sensory characteristics of Assyrtiko wines based on acidity. For this purpose, the Lachancea thermotolerans species, known for relatively extensive fermentation ability, low acetic acid production, and especially formation of lactic acid, was tested in sequential fermentation with three different Saccharomyces cerevisiae strains, isolated from the Greek terroir. At the end of fermentation, enological parameters were determined according to OIV protocols and the volatile compounds produced were measured by gas chromatography-mass spectrometry. Finally, all wines were evaluated using quantitative descriptive analysis by two groups of experts: a Greek team of enologists from Santorini Island, specialized in Assyrtiko wines, and a French team of enologists from Bordeaux. As expected, the inoculated strain dominated the fermentation process, but nine indigenous S. cerevisiae strains were also identified. L. thermotolerans produced 1 g/L lactic acid, while also modulating the volatile profile of the wines independently of the S. cerevisiae strain used. The origin of the panelists played an important role in bringing up sensory traits such as acidity and sweetness. Our results suggest a new and interesting application of L. thermotolerans for white wine production.

Funding Support: This research has been co-financed by the European Union and Greek national funds through the Operational Program for Competitiveness, Entrepreneurship and Innovation, under the call “Greece – Israel Call for Proposals for Joint R&D Projects 2019” (project code: T10ΔΙΣ-00060)