## 5 Conclusions  
So far, at least to our best knowledge, there has been no research on Merlot or any other grape variety that has simultaneously investigated the influence of the environmental and technical factors of cluster thinning and the type of alcoholic fermentation on the composition of volatile compounds (VOCs) and on the sensory characteristics of the wine in successive vintages. Testing all three factors on grapes of the same origin and two vintages has significant added value compared to separate trials for each factor and provides important conclusions for the industry. All the above factors can have a significant influence on the wine composition, as has been shown separately in many other studies and already mentioned, but the results obtained in our study are an important contribution to classifying their influence and understanding their interaction with the vintage effect. Furthermore, the influence of cluster thinning on the composition of VOCs and the sensory characteristics of the wine in more than one-year experiments has been studied far less than its influence on other parameters of wine and fruit composition, so our study also adds some original insights to this area of research, clearly showing that under our experimental conditions it had only a minor influence on the quantified VOCs in wine. The following main conclusions can be drawn from the results: (i) of the three factors examined in our experiment, the composition of Merlot wine was largely determined by the vineyard location. ; (ii) spontaneous alcoholic fermentation has a greater influence on the wine composition than cluster thinning; (iii) both the location of the vineyard and spontaneous alcoholic fermentation influenced significant differences in the sensory characteristics of the wine, while cluster thinning had no such influence; and (iv) spontaneous alcoholic fermentations can reduce the effects of vintage on the wine composition, while the opposite is true for cluster thinning. **Supplementary Materials:** The following supporting information can be downloaded at [[https://www.mdpi.com/article/10.3390/foods14071101/s1](https://www.mdpi.com/article/10.3390/foods14071101/s1)]([https://www.mdpi.com/article/10.3390/foods14071101/s1](https://www.mdpi.com/article/10.3390/foods14071101/s1)), Figure S1: Monthly average temperatures (lines) and precipitation (histograms) (left graph) and monthly growing degree days (GDDs) (right graph) for vintages 2020 (a) and 2021 (b), at locations B and M; Figure S2: Yeast cell concentration (log CFU/mL) (upper plots; the mean values and standard deviations of three repetitions per treatment are displayed) and yeast population dynamics during spontaneous (M-C_sAF) and inoculated (M-C_iAF) alcoholic fermentations of Merlot mash from location M (middle and lower plots; the mean values of three repetitions and the values for the relative abundance above 1% are shown); vintage 2020-left, vintage 2021-right; Figure S3: Yeast cell concentration (log CFU/mL) (upper plot; the mean values and standard deviations of three repetitions per treatment are displayed) and yeast population dynamics during spontaneous (B-C_sAF) and inoculated (B-C_iAF) alcoholic fermentations of Merlot mash from location B in 2021 (middle and lower plots; the mean values of three repetitions and the values for the relative abundance above 1% are shown); Table S1: Date, day of the year and growing degree days (GDDs) accumulation for the phenological stages of the Merlot variety at location B for the 2020 and 2021 vintages; Table S3: Viticultural parameters at both locations (M, B) and crop loads (C, CT) in both vintages (2020, 2021); Table S4: Berries fresh mass and must parameters at both locations (M, B) and crop loads (C, CT) in both vintages (2020, 2021); Table S5: Reducing sugar (RS), malic acid and lactic acid concentrations in the experimental Merlot wines from two locations (M, B), two crop loads (C, CT) and two vintages (2020, 2021) after finishing inoculated (iAF) and spontaneous (sAF) alcoholic fermentation.