Use of non-Saccharomyces yeasts to modulate oenological parameters in Albillo Mayor white wines

The white Albillo Mayor grape variety is considered aromatically neutral. Fermentations with non-Saccharomyces yeasts could substantially improve the aromatic profile and the acidity of these wines. The aim of this work is to evaluate the use of selected strains of different non-Saccharomyces species to improve the quality of Albillo Mayor white wines. Fermentations in duplicate stainless steel barrels of 150 L of volume were carried out at Bodegas Comenge, Ribera del Duero, Spain. All fermentations were sequentially inoculated with Saccharomyces cerevisiae. The fermentations were carried out with the species Hanseniaspora vineae, H. opuntiae, two strains of Metschnikowia pulcherrima (M29 and M54) and a mixed fermentation where an inoculum with M. pulcherrima and Lachancea thermotolerans species was added in a 1:1 ratio. The results indicated an increase in total acidity of 1.8 g/L in the mixed fermentations resulting in 0.2 units of pH reduction. M. pulcherrima produced more than twice the 2-phenylethanol content of the control wines. Values for all terpenes were higher in H. vineae fermentations, with the exception of nerol, with higher contents in M. pulcherrima M54 fermentations. Tasters perceived the M29 wines of M. pulcherrima as the most balanced and cleanest. In addition, together with the wines from the mixed fermentations, they were perceived as having the highest varietal aromatic character. It should be noted that the higher acidity, analytically identified in the mixed fermentations, was not perceived by the tasters. The use of non-Saccharomyces yeasts can modulate oenological parameters such as acidity or the release of fermentative volatiles in Albillo Mayor wines.