Impact of yeast on the characteristics of Sauvignon Blanc wines from the Campanha Gaúcha Region

The objective of this work was to evaluate the effect of different commercial strains of Saccharomyces cerevisiae on the characteristics of Sauvignon Blanc wines produced in the Campanha Gaúcha region. The must obtained by mechanical destemming and crushing was treated with 150 mg L of potassium metabisulfite and pectolitic enzymes and subject to enzymatic hidrolisis and débourbage for 24h00 at 4°C. The must was divided into glass fermenters of 4,6 L, in triplicate for each of the four treatments, which were defined by the inoculation of 25g hL-1 of dry yeast: T1 - Zymaflore X5® (Laffort, Bordeaux, France); T2 - AWRI 796 (AB Biotek, Sydney, Australia); T3 - Maurivim PDM (AB Biotek, Sydney, Australia); T4 - 50% Zymaflore X5® + 50% AWRI 796. The wines were analyzed, regarding: ethanol; reducing sugars; total acidity; volatile acidity; pH; dry matter; and ash. The most significant differences were observed in: ethanol; reducing sugars; pH; dry matter. Among the treatments inoculated with single strains, T1 showed higher ethanol and lower reducing sugars content. T3 presented results similar to T1. T2 resulted in higher content of reducing sugars and consequently lower ethanol levels. The mixed fermentation (T4) achieved the lowest levels of reducing sugars among the treatments. It suggests that mixed fermentations could be an alternative to produce drier wines.