Deciphering Terroirs’ Code: Vineyard Site Selection for Phenolic Performance in ‘Kalecik Karası’ Grape Cultivar (V. vinifera L.)

Abstract

Understanding the complex interplay between environmental factors and grape quality is crucial for the viticulture industry, as it directly influences wine quality and the distinctiveness of products. This significance underpinned our comprehensive study, which aimed to dissect the relationships between ‘terroir’, including the altitude, regional climate, soil characteristics, vineyard management practice, and the composition of grapes in cv. ‘Kalecik Karası’ (Vitis vinifera L.). Six vineyard sites ranging from 115 to 1180 m altitude were studied. Total soluble solids (TSS, °Brix) titratable acidity, pH and color index of red grapes (CIRG) were evaluated as the main maturity indices and phenolic composition based on anthocyanin and tannin was analyzed. According to the results of the study, we deduced the critical importance of adopting region-specific viticultural practices tailored to the unique environmental conditions of each terroir. This approach not only optimizes grape quality but also accentuates the uniqueness of the wines produced, reflecting the inherent qualities of their origin. The highest altitude Nevşehir (1180 m) showed high levels of total and extractable anthocyanin highlighting the region’s favorable conditions for these compounds (355.26 mg kg⁻¹ and 364.00 mg kg⁻¹), while exhibiting the second lowest skin tannin (1979.40 mg kg⁻¹ and 2180.78 mg kg⁻¹) in both years. Particularly for cultivars like ‘Kalecik Karası’, our study demonstrated how specific terroirs could significantly affect their phenolic composition and, consequently, wine quality. By aligning viticultural practices with the distinct characteristics of each terroir, producers can enhance both the quality and distinctiveness of their wines. This emphasizes the necessity of ongoing research and adaptation in viticultural strategies to fully harness the potential of diverse grape varieties and terroirs, ensuring the production of high-quality wines that truly reflect their origin.