## 3 Results and Discussion
### Volatile Composition  
Among the different volatile compounds, a total of 18 were selected because they represent the four most abundant families (esters, acetates, alcohols, and fatty acids) of wines after carrying out the alcoholic fermentation. As shown in Table 3, these were analyzed in base wines (BW) and canvas, after 18 months of aging bottled on lees (18M). Table 3 shows the total volatile concentration of the base wines and canvas. In general, and as expected, there was an aromatic decrease between the analysis times, before triage in base wines (BW) and after 18 months of aging on lees (18M) as previously observed in other studies [28]. When observing BW values, a higher content of volatiles was found with the XA variety. However, when comparing the different yeasts, both varieties of wine showed the same trend. Thus, the volatile content was similar regardless of the yeast used, except when Y3 was used, which presented significant differences with respect to the other yeasts and provided the lowest volatile concentration. Regarding the values after 18 months of aging on the lees, the aromatic content values were similar between varieties; thus, considering its higher volatile contents in base wine, XA suffered a greater decrease. When observing each of the varieties independently, greater significant differences were observed between the five yeasts used with respect to BW. In addition, the yeast _T. delbrueckii_ (Y5) stood out in both varieties, with which high values of aroma concentrations were obtained, similar and/or higher than those obtained by some _Saccharomyces_ yeasts. To better study the results obtained, the different chemical families were separately studied. Thus, in relation to esters, in general these showed the same trend as the one described above for total aromas (Table 3). This behavior is due to the fact that the esters are the most abundant chemicals found in wine aroma and, therefore, are those that contribute the most to the total aroma. Furthermore, this family is of great importance because it provides the two important descriptors, fruit and flowers [29; 30]. The base wines with non-_Saccharomyces_ yeasts (Y4 and Y5) presented the highest concentrations of esters in CH, and values equal to or higher than the other _Saccharomyces_ yeasts in XA. After 18 months of aging on the lees, higher amounts of esters were found when using Y2 and Y5 and, when dealing with XA cavas, also Y1. With reference to the different esters found, the highest concentrations of ethyl butyrate, ethyl isovalerate, ethyl hexanoate, ethyl octanoate, and ethyl decanoate were observed in Y2 and Y5 in CH at 18 M (Table S2). Y5 also showed the highest value of ethyl isovalerate in XA cavas. These compounds are directly related to the fruity notes of pineapple, apple, pear, anise, and flowers (Table S2). Furthermore, in general, all of these compounds presented concentrations well above their sensory limit (Table S2), with the exception of ethyl butyrate, which only exceeded it in some cases. Therefore, non-_Saccharomyces_ yeasts, such as _T. delbrueckii_ (Y5), presented and conserved the same or higher concentrations of esters than some _Saccharomyces_ yeasts.