Indigenous yeasts associated with two Vitis vinifera grape varieties cultured in southern Spain

The yeast microbiota present on the surface of grapes of two Vitis vinifera varieties, Pedro Ximenez and Tempranillo de Rioja, grown in the Montilla-M oriles region of southern Spain was identified. The changes between veraiso n and the physiological ripeness time during 3 years were monitored. Overal l, the yeast microbiota isolated was of oxidative metabolism. Sporobolomyce s roseus and Cryptococcus albidus species occurred at all physiological sta ges, in the two Vitis vinifera varieties, and the three seasons studied. On the other hand, Kloeckera apiculata was never detected and Saccharomyces c erevisiae was scarcely isolated, it was only present, testimonially, in Tem pranillo de Rioja grapes during the 1992 vintage. The widest variety of yea st species was observed in the 1992 season, and in contrast, the lowest num ber of species in both varieties of Vitis was detected in the 1994 season.