# Exploring Red Wines from the Drama Region: A Chemical, Sensory, and Terroir Insight
## 3 Results and Discussion  
### Physicochemical Parameters of Grapes and Wines  
The synthesis of phenolic compounds is greatly influenced by several environmental conditions. Three experimental locations were selected for the Cabernet Sauvignon and Agiorgitiko grape varieties, while for Merlot, four. The vineyards' altitudes ranged from 100 m (Cs-Mi) to 890 m (Me-Nv) with comparable growing circumstances for the current study, and temperature was the main climate component influenced by height. Altitude has a significant impact on site temperature, affecting air, berry, and soil thermal values [5], as shown by the data in Figure 1 and Table 1.  
Altitude is one of the key geographic factors affecting the composition and quality of wine produced at a specific location. Generally speaking, high-altitude growing locations can support an increase in the content of numerous chemical compounds present in grapes and wine, including trihydroxylated flavonoids, carotenoids, isoamyl acetate, ethyl hexanoate, catechins, quercetin derivatives, cyanidin-derived anthocyanins, total polyphenols, and total monomeric anthocyanins, albeit at varying intensities. The altitude factor, however, appears to vary by cultivar; in fact, it may have a favorable impact on the levels of total aroma compounds and acylated anthocyanins in some cultivars (like Glera) and a negative impact on the same components in other cultivars (like Merlot and Cabernet Sauvignon). It may also have varying effects on the polyphenol concentration in various regions of the same plant, i.e., in Syrah grapes, it has been discovered that an increase in altitude causes a decrease in seed tannins and an increase in skin tannins. Furthermore, because more anthocyanins, flavonoids, and tannins are synthesized at higher elevations, an increase in UV-B radiation might cause the intensification of the color [23]. Vineyards at higher elevations exhibited a delay in budburst and blooming, which was linked to the temperature decreasing with height, typically in the range of 0.65 to 1.0 \({}^{\circ}\)C for every 100 m gain in elevation. High-altitude vineyards have the greatest potential to produce high-quality grapes (with better acidity and lower alcohol levels) under future warmer temperatures, resulting in maximum terrorin expression because they ripen later during the milder months [23]. As the temperature rises, grapes' total tittatable acidity (TA) decreases. [PERSON] et al. [24] demonstrated that, in comparison to a vineyard at a 650 m altitude, a vineyard at 500 m with a higher mean air temperature had lower TA and higher pH and TSS/TA ratios in the \"Niagara Rosada\" and \"Isabel\" cultivars. This was also the case for Merlot grapes produced at various elevations, in our study. The results from the physicochemical study of grapes and wines are reported in Tables 2 and 3. It is visible that location affects all the physicochemical parameters of must. Although the altitude is expected to affect these parameters, it is visible that the altitude factor seems to be cultivar-dependent. The weight of the grapes from Merlot and Cabernet Sauvignon was significantly affected by the vineyard location, while that from Agiorgitiko was not. Temperature is one of the most critical environmental factors influencing grape berry growth, composition, and overall quality. Concerning the Merlot grapes, our results show that warmer sites produce grapes with a higher berry weight. However, other authors described that the warmer conditions during berry growth and ripening enhance evapotranspiration, leading to berry dehydration and a lower final weight [25]. Especially for Merlot grapes, those from the Nevrokopi vineyard were visibly smaller than those from other locations, although having a similar grape weight. This could be attributed to both altitude and soil composition. The Nevrokopi vineyard is situated at the highest elevation and is characterized by sandy loam soil, while the other locations have a much lower elevation and clay and loamy soils.