## 2 Results
### Volatile Profile of Base Wines and Sparkling Wines  
S Sixty-two and sixty-six compounds, present in Ribolla Gialla base (Supplementary Materials Table S1) and sparkling wines (Supplementary Materials Table S2), respectively, were semi-quantified and separated according to their chemical classes (monoterpenes, norisoprenoids, aldehydes, alcohols, esters, acids, and ketones) and the three-ways ANOVA was applied to investigate the main effects of crop level, location of the vineyard and season. \begin{table}
\begin{tabular}{l c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multicolumn{3}{c}{**T******************} & \multicolumn{3}{c}{**Size (\%)**} & \multicolumn{3}{c}{**Year (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} & \multirow{2}{*}{**Size (\%)**} \\ \cline{2-  
In the case of base wines (Supplementary Materials Table S1), the CT treatment significantly affected only a very scarce number of individual aroma compounds compared to the control. Among monoterpenes, linalool was the only significantly increased compound after the thinning treatment. Similarly, the concentration of isoamyl alcohol and _cis_-3-hexenol was significantly enhanced by CT, together with the total concentration of alcohols. Concerning the other aroma classes, norisoprenoids and aldehydes were nearly unaffected by the CT treatment. At the same time, a non-significant increase in esters and reduction of acids and ketones occurred. On the other hand, more metabolites were affected by vineyard location and mostly by the season. Several compounds revealed higher concentrations in FCO wines, including sensory-important linalool and limonene. Among norisoprenoids, \(\beta\)-damascenone contributed the most to the significant differences between sites and seasons. Concerning the groups of fermentation-derived compounds, an increased concentration of alcohols and aldehydes was predominantly observed in the wines originating from the FCO location. Similar findings apply to most esters, acids, and ketones, apart from methyl ethyl succinate, diethyl succinate, ethyl 9-decanoate and 2-methylthiolan-3-one significantly prevailed in the wine samples produced from the FG vineyard located in the valley floor. The statistical analysis revealed many differences related to the seasonal factor, mostly caused by the meteorological peculiarities. The concentration of most of the examined compounds was higher in the year 2017, while the lowest values were found in the season 2018 because of both the higher yield and the lower accumulation of sugars in berries. As in the base wines, the location and mostly seasonal factor had a significant effect on the volatile profile of sparkling wines (Supplementary Materials Table S2). However, the products obtained after the secondary fermentation showed a higher degree of sensitivity to the CT treatment, with a significant increase of the concentration of citronellol, linalool and \(\beta\)-myrcene by 13%, 9% and 14%, respectively, than UNT. Among the aldehydes, _trans_-2-hexenal and acetaldehyde increased significantly in CT sparkling wines. A similar effect was also observed in the case of alcohols, where isoamyl alcohol, 2-phenylethanol and isobutanol accounted for the most important higher alcohols found in sparkling wines. Ethyl lactate, diethyl succinate, and ethyl-9-decanoate were shown to be the most affected esters in a positive manner. The composition of acids was similar between base wines and sparkling wines. The effect of thinning concerned mainly the concentrations of acetic acid and benzoic acid.