Effect of terroir on grapes and wine

The word 'Terroir' comes from root 'terre' which means earth or soil. But in the world of wines, the terroir concept is more than just soil. Where some classify terroir as an interactive cultivated ecosystem in a given place including soil, climate, and the vine; some define it as a combination of natural environment plus biological and human factors. We can say that the terroir concept is based on an assumption that the key wine characteristics attribute to a fixed geographical area where the grapes and the wine are produced.                                     

How to study a terroir?

The terroir is one of the most widely-discussed subjects in winemaking and is highly accepted in established regions, be it any part of the world. Since many factors related to both the plant and the physical environment are involved in defining a terroir, it is advised to opt a pluridisciplinary approach for studying a terroir.

Is terroir responsible for wine's sensory attributes?

Yes. To understand the concept of terroir and its influence on wine composition along with sensory attributes, the spatial and temporal variability of key wine aroma compounds should be known. These are ­­3-mercaptohexanol (‘tropical’ and ‘grapefruit’ notes), 1,8-cineole (‘minty’ and ‘eucalypt’ aromas), and rotundone (‘peppery’ and ‘spicy’ notes). Various studies on these aroma compounds suggest that the environmental and biological interactions along with biotic factors like vintage and winemaking procedures, play important roles in shaping a wine's composition and its sensory attributes.

What takes for a grape to express the terroir?

The precocity of the grapevine variety is the first condition for a great terroir expression. It should match with the local climatic conditions in such a way that full ripeness of the fruit is reached by the end of the growing season. The second condition is that the vines should experience a factor which limits the yield and vigour. For example, water deficit stress or low nitrogen availability in the soil. Please note, even a single wine region may have varied terroir. Sometimes, a single wine grape variety grown on a specific block in a single

vineyard may produce different tastes than the one (with same variety) grown in another block. This is enough to tell how wide the concept of terroir is.