BASE WINE AND TRADITIONAL SPARKLING WINE MAKING USING TORULASPORA DELBRUECKII KILLER YEASTS

The killer strains of Torulaspora delbrueckii can be used to improve the dominance of this yeast during must fermenta­tion. The present work analyzes its usefulness for traditional spar­kling wine making (base wine and cava). T. delbrueckii killer strain dominated base wine fermentation better than non-killer strains and produced dried wines. The foam ability of T. delbrueckii base wines was very low compa­red to that of Saccharomyces cerevisiae. Significant posi­tive correlations of foam parameters were found with the amounts of C4-C16 ethyl esters and proteins, and negative correlations with some antifoam alcohols. The organoleptic quality of T. delbrueckii base wines was considered inap­propriate for cava making. While S. cerevisiae (alone or mixed with T. delbrueckii) completed the second fermen­tation to produce dry sparkling wines with high CO₂ pres­sure, T. delbrueckii alone did not complete this fermen­tation, leaving sweet wines with low CO₂ pressure. Death due to CO₂ pressure was much higher in T. delbrueckii than in S. cerevisiae, making any killer effect of S. cerevi­siae on T. delbrueckii irrelevant. However, the organo­leptic quality of cava inoculated with mixtures of the two yeast species was better than that of wine inocula­ted exclusively with S. cerevisiae, and no deterioration in the quality of the foam was observed.