Dynamics of Saccharomyces cerevisiae population in spontaneous fermentations from Granxa D’Outeiro terroir (DOP Ribeiro, NW Spain)
Granxa D’Outeiro is a recovered ancient vineyard located in the heart of DOP Ribeiro, where traditional white grapevine varieties are growing under sustainable management. Spontaneous fermentations using grape must from Treixadura, Albariño, Lado, Godello, and Loureira varieties were carried out at experimental winery of Evega. Yeasts were isolated from must and at different stages of fermentation. Those colonies belonging to Saccharomyces cerevisiae were characterized at strain level by mDNA-RFLPs. General chemical parameters and aroma profile of wines were determined using official OIV methodology and GC analysis. The microbiological control of fermentations revealed the presence of 5 to 15 different strains of S. cerevisiae depending on the variety. The highest diversity of yeast strains was found in Loureira fermentation. Strains named as G3 and G4 were the dominant yeasts in all processes, except Godello (controlled by strain G11); therefore, they are the main responsible for the fermentative aromas of the wines. The total acidity of wines ranged between 4,2 g/L with Treixadura and 5.2 g/L with Loureira, while the alcohol content ranged between 13 % (v/v) with Loureira and 14,2 % (v/v) with Lado. Treixadura wines showed the highest concentration of fermentative volatile compounds and this variety and Loureira reached the highest content of terpenes and eugenol. A blend of these monovarietal wines will allow to obtain an exclusive wine, which expresses the biodiversity from Granxa D’Outeiro terroir.
Acknowledgements: Project FEADER 2022/009A financed with funds from FEADER (75%), Xunta de Galicia (22.5%) and Ministry of Agriculture, Fisheries and Food (MAPA) (2.5%)
Issue: ICGWS 2023
1 Estación de Viticultura e Enoloxía de Galicia (EVEGA-AGACAL), Ponte San Clodio s/n, 32428, Leiro-Ourense
2 A Granxa D’Outeiro, Francelos, Ribadavia, Ourense, 32418-Coordenadas (42.2745221, -8.1626866)
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Granxa D’Outeiro, traditional grapevine varieties, spontaneous fermentation, Saccharomyces cerevisiae, yeast strains, wine chemical composition