## 3 Results and Discussion
### Wine Composition  
As expected, the alcohol content in wine corresponded to the results of soluble solids in grape juice. In both years of study, the practice of cluster thinning increased the alcohol content in wine, whereas a reduction was obtained via severe shoot trimming (Table 3). The same corresponding results occurred with pH, which was increased via CT in both years. On the other hand, insignificant differences were observed between CT and FC for titratable acidity, though it tended to be lower in CT. Interestingly, though the effect of  
Figure 3: Variation in soluble solids (Brix) in 2017 and 2018; total anthocyanins expressed as mg/g and mg/berry in 2017 and total phenolics expressed as mg/berry in 2017 for the different combinations of treatments (FC-HC—full crop combined with high canopy; FC-SST—full crop combined with severe shoot trimming; CT-HC—cluster thinning combined with high canopy; CT-SST—cluster thinning combined with severe shoot trimming). Data were analyzed via one-way ANOVA in randomized blocks design. Different letters indicate significantly different means. cluster thinning on berry phenolic composition was in most cases insignificant, the phenolic composition of wine was largely affected by this practice; that is, CT wines had significantly higher concentrations of total anthocyanins in both years of study than FC, whereas the differences in berries were not significant. A similar outcome was reported in some other studies [56; 57], where the viticultural treatments did not change the concentration of anthocyanins in the berries, followed by their significant increase in the respective wines. Given that the concentration of extractable anthocyanins increases in the final stages of berry ripening [58] and higher anthocyanin concentration in wines can be obtained from grapes which are more ripe [59], we hypothesize that the observed discrepancies in the concentration of total anthocyanins in berries and wines of CT-treated wines are related to changes in skin cell wall material, which occur during the ripening period [60]. Similarly, although no significant differences were observed in the concentration of total phenolics in berries, CT obtained significantly higher concentrations of total phenolics in wine in 2018. This variability was most likely caused by the ethanol concentration in the wine, which results from the permeability of the cell walls and membranes that are mostly affected by factors such as the presence of ethanol, which causes a more significant release of phenols located in the inner-thick cells of the skin's hypodermis [61]. According to several studies, higher ethanol concentration leads to higher concentrations of total phenolics, tannins and non-tannin phenolics in wine [59; 62], which was the case for the CT treatment compared to FC. The color intensity of the wines did not differ significantly between treatments, though a tendency toward more intense coloration was observed in CT compared to FC in both years; this trend was probably due to higher concentration of total anthocyanins in CT and the fact that higher ethanol concentration favors the formation of polymeric pigments, which result in darker wines [59]. Anthocyanins are responsible for the color of red wines and their interactions with other phenolic compounds are of crucial importance in determining wine color [63]. Apart from the reduced alcohol content in wine, severe shoot trimming had no other significant impact on wine composition, confirming the findings obtained by some previous studies, which reported that late source limitation does not negatively impact the concentration of anthocyanins or phenolic compounds in wine [28; 30; 33; 34; 35]. Following the response observed for the sugar content in grape juice, the interaction between the two investigated factors was also obtained for the alcohol content in wine (Table 3).