Effect of alternative techniques to ageing on lees and use of non-toasted oak chips in alcoholic fermentation on the aromatic composition of red wine

The aim of this work was to evaluate the effect of different enological treatments on the volatile composition of red wine: ageing on lees with and without adding β-glucanase enzymes; the use of a commercial yeast derivative with and without β-glucanase enzymes; and the use of non-toasted chips in fermentation. The results indicated that the presence of chips during the fermentation enhanced the formation of 2-phenylethanol, ethyl esters and fusel alcohol acetates, but affected the levels of some of the lactones and volatile phenols studied negatively. In addition, it was found that wine lees and commercial yeast derivatives can bind some of the volatile compounds studied, mainly ethyl esters and fusel alcohol acetates. After 6 months in bottle, in general, the differences found between the control wine and wines fermented with chips were maintained. However, between the control wine and the wines treated with natural or commercial yeast, the differences disappeared, although not for all the compounds studied. Finally, an important effect of the addition of β-glucanase enzymes was not observed.