# Exploring Red Wines from the Drama Region: A Chemical, Sensory, and Terroir Insight
## 3 Results and Discussion
### Physicochemical Parameters of Grapes and Wines
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Altitude (m)** & **Wine pH** & **Wine TA (g/L** & **wine VA (g/L** & **Alcohol (\%vol)** & **Residual Sugars** & **Malic Acid (g/L)** \\  & & \(-\)0.337\({}^{*}\) & & \(-\)0.580\({}^{**}\) & 0.408\({}^{**}\) & \\  & (0.018) & & (0.000) & (0.009) & \\ \hline \multirow{2}{*}{**Days to harvest**} & \(-\)0.355\({}^{*}\) & & & & \\  & & (0.025) & & & \\ \hline \multirow{2}{*}{**Weight of 100 grapes (g)**} & \(-\)0.517\({}^{**}\) & & & \(-\)0.315\({}^{*}\) & \(-\)0.417\({}^{**}\) \\  & & (0.001) & & & (0.048) & (0.007) \\ \hline \multirow{2}{*}{**Must sugar content (Be)**} & \(\begin{array}{c}0.567\,^{**}\\ (0.000)\end{array}\) & & \(-\)0.335 \({}^{*}\) & \(-\)0.346 \({}^{*}\) & 0.870 \({}^{**}\) & \\  & (0.003) & (0.035) & (0.029) & (0.000) & \\ \hline \multirow{2}{*}{**Must acidify (g/L** & \(-\)0.456 \({}^{**}\) & & 0.404 \({}^{**}\) & 0.350\({}^{*}\) & \\  & (0.003) & & (0.010) & (0.027) & \\ \hline \multirow{2}{*}{**Must pH**} & \(\begin{array}{c}0.586\,^{**}\\ (0.000)\end{array}\) & & & & \\  & & (0.000) & & & \\ \hline \multirow{2}{*}{**YAN (mg/L)**} & \(\begin{array}{c}0.613\,^{**}\\ (0.000)\end{array}\) & & \(\begin{array}{c}0.513\,^{**}\\ (0.001)\end{array}\) & \(-\)0.361 \({}^{*}\) & & \\  & (0.000) & & (0.022) & \\ \hline \hline \end{tabular}  
* In parenthesis, significance values.
* Correlation is significant at the 0.05 level (2-tailed). *
* Correlation is significant at the 0.01 level (2-tailed).  
\end{table} 
Table 4: [PERSON]’s rho correlation coefficient between the must and wine parameters studied. climate and grape cultivar traits have a greater impact on amino acid concentrations than altitude alone. Our results show that Drama's higher-altitude vineyards, in contrast to lower-altitude locations, sustain noticeably greater TA levels. This is consistent with the earlier research in other wine-producing areas, like the Douro Valley in Portugal [32] and Mendoza, Argentina [33], where the altitude was found to reduce acid degradation because of delayed ripening and lower overnight temperatures. Drama's observed acid retention indicates that vineyards at higher elevations are naturally better able to maintain wines' freshness and balance, which are distinctive characteristics for the development of both white and red wines. Furthermore, comparable studies carried out in Greek vineyards [6] verified that vineyards at higher elevations have lower levels of organic acid respiration, especially malic acid. Table 3 reports the phytochemical parameters of wines produced utilizing the must from grapes of cultivars Merlot, Cabernet Sauvignon, and Agiorgitiko grown in different locations of the Drama region. It is visible that wine acidity (TA) and malic acid do not differ among the locations for the three cultivars studied. Regarding the pH, VA, alcohol, and residual sugars, a significant effect of cultivar in the variation induced by location was observed. Growing year (often referred to as vintage) significantly affects TA, malic acid, and alcohol % content; TA and malic acid content decreased in 2023, while alcohol content increased compared to 2022. Variations in annual climatic conditions, such as temperature, sunlight, and rainfall, directly impact grape composition, thereby affecting these key wine parameters. Warmer growing seasons accelerate the breakdown of malic acid in grapes, leading to lower overall acidity at harvest. Conversely, cooler seasons slow this degradation, resulting in higher levels of acidity [34]. In general, the rest of the parameters were stable during the two growing years. Specifically, regarding the amount of malic acid and pH in wines, it was found that this depends on the cultivar, with Agiorgitiko showing the lowest values. Similar pH values for Cabernet Sauvignon grapes were reported by other researchers [35]. The pH of grape juice and resulting wine is influenced by the concentration of organic acids, primarily tartaric and malic acids.