Influence of vintage and selected starter on Torulaspora delbrueckii/Saccharomyces cerevisiae sequential fermentation

The practice of sequential fermentation of grape juice with a Saccharomyces cerevisiae starter strain coupled with a selected culture of a non-Saccharomyces yeast is used to improve the sensory profile and add complexity of wines. In this study, the effect of Torulaspora delbrueckii/S. cerevisiae sequential fermentation on Verdicchio wine under winery conditions was investigated, evaluating grape juices of three different vintages and two S. cerevisiae starter strains. In the 3 years of examination, some of oenological characters of the final wines were influenced by grape juices coming from different vintages. However, in all cases, T. delbrueckii/S. cerevisiae sequential fermentation influenced the analytical profiles of the Verdicchio wines according to the S. cerevisiae starter strain used. Indeed, different behaviours were found for the same T. delbrueckii strain together with the autochthonous Sc151 or the commercial VIN13 S. cerevisiae yeast, indicting that the yeast-yeast interaction plays an important role in analytical profile of wines. On the other hand, specific contributions were seen with T. delbrueckii, which is inoculated in sequential fermentation for three consecutive vintages using different starters.