Unveiling terroir: evaluating the magnitude of the heterogeneity and its main drivers in the Canary Islands wines

The Canary Islands are a Spanish archipelago of volcanic origin in the Atlantic Ocean near the Saharan coast. The extensive intricacy and multitude of variables inherent in the Canary Islands winemaking tradition have posed a substantial challenge, preventing comprehensive research on the main factors contributing to the character of local wine, thus, far. This challenge arises from a convergence of factors including the presence of 14 different grape varieties, and radically different climatic, soil and geographic conditions. This investigation sought to start unraveling this complexity by discerning the impacts of various geographical (specifically, island-related) and management factors (namely, organic vs. conventional practices) on soils and wines within the Canary Islands. Additional variables, such as wine type (red and white) and island of origin, were explored and correlated with the chosen management system. Pairs of organic and conventional wine and soil samples, possessing similar characteristics, were systematically collected from each of the seven wine-producing islands in the Canary archipelago. An examination of elemental composition, oenological attributes and fertility parameters was conducted, followed by comprehensive statistical analysis. Among the variables examined, only the island of origin emerged as statistically significant within the sample. Concerning soil fertility, organic samples exhibited elevated levels of organic matter compared to their conventional counterparts. No notable disparities were observed between the two production methods in terms of soil metal composition and other fertility parameters. However, it is noteworthy that four soil samples surpassed the legally permissible limits for Nickel (Ni) and Mercury (Hg), with three of these instances originating from Lanzarote.