In a different experiment, all the selected strains were used for the fermentation of a red Grenache must (15% expected ABV) with two different amounts of YAN, 210 and 295 mg/L. Fermentation kinetics was faster in high nitrogen content musts than in low nitrogen musts. In fact, 13 days after inoculation mean of residual sugars in musts of YAN 210 mg/L was 35.44 g/L, significantly higher than in musts of YAN 295 g/L (8.06 g/L). A multivariate analysis of variance carried on red Grenache wines with nitrogen content and strain as main effects, shows that levels of acetic acid in wines made
with low nitrogen addition (mean ¼ 191.53 mg/L) were significantly lower than in wines made with higher nitrogen addition (mean ¼ 412.32 mg/L). This result shows that an excess of nitrogen in must can lead to a not desired increase in volatile acidity, and points to the importance of grape must nitrogen content on final wine quality, as already described (Bell & Henschke, 2005).