Use of Torulaspora delbrueckii and Saccharomyces cerevisiae in semi-industrial sequential inoculation to improve quality of Palomino and Chardonnay wines in warm climates.

Abstract

We have evaluated for the first time the impact of two commercial yeast strains (Torulaspora delbrueckii TD291 and Saccharomyces cerevisiae QA23) inoculated sequentially in musts of Chardonnay and Palomino Fino grape varieties grown under warm climate (South-west of Spain). Semi-industrial scale alcoholic fermentations (AF) were performed during the 2011 and 2012 harvests. Implantation analyses demonstrated that T. delbrueckii is the predominant strain until the end of the AF phase. Wines with sequential inoculation (SI) resulted in the production of low levels of acetic acid (which gives wine an undesirable 'vinegary' character), low acetaldehyde in Chardonnay and high in Palomino wines. The most salient attributes that contribute to the quality of the Chardonnay and Palomino wines produced were aroma intensity, fresh and tropical fruit character. This study demonstrated that SI of T. delbrueckii and S. cerevisiae contribute significantly to the improvement of Chardonnay wine aromas and the creation of new styles of wine for Palomino. This study has generated new knowledge about the biotechnological potential of T. delbrueckii (TD219) and S. cerevisiae (QA23) for improving the organoleptic properties of Chardonnay and Palomino wines.