OENOLOGICAL CHARACTERISTICS OF SALTAÑA WINE YEASTS

The oenological study of indigenous wine yeasts is of importance for the selection of possible winemaking starters.It is necessary to identify enological characteristics useful at the industrial level in the winery, such as fermentation power, fermentation speed, killer activity, development at different temperatures, growth in increasing amounts of alcohol and sulfur dioxide.The selected yeasts were isolated from Malbec and Cabernet Sauvignon grapes from Cafayate, Salta; identified according to Yarrow's (1998) taxonomic techniques as Sacharomyces cerevisiae and confirmed by molecular taxonomy.The killer phenotype of the isolated strains was evaluated by the method of Sommers and Bevan (1969), measuring the inhibition and death halos of the sensitive strain NCYC 1006.The fermentative power of the killer strains was determined according to the Delfini-Ciolfi (1979) technique by the production of carbon dioxide by daily weighing, evaluating the % alcohol by volume and the fermentation speed, selecting the yeasts that have high ethanol yield and better fermentation speed.The results indicate that the strains isolated from Malbec and Cabernet Sauvignon grapes with the best killer characteristics, determined by the inhibition and death halos of the sensitive strain NCYC 1006 of 4.8 and 3.22 mm, respectively, registered the highest values of 86.8 and 84.4 g/L of carbon dioxide produced, with growth rates 1.5 times the total rate, adequate for a winemaking process.