The unseen element

Wednesday, 28 July, 2004
Leonie Joubert
Wind is to terroir what chillies are to a Thai curry - you don't see much of the ingredient, but it is crucial in the journey of a grape towards becoming superior wine.

Well, that's what winemakers will have you believe. In the mysterious workings of terroir in the conjuring of flavours in the berry, every farmer (no matter how far from the ocean or hidden behind mountains) will lay claim to the fabled influences of 'cooling sea breezes' on the delicate ripening fruit.

Certainly, we know that cool breezes are important in keeping vineyards chilled when summertime temperatures reach their peak but now science might have proved that there's more to wind than just wishful thinking.  

Wind, it's just been discovered, might actually alter the chemical composition in a grape berry and, by extension, shape the flavour in the final product.

Scientists at the University of Stellenbosch's viticulture department conducted experiments on separate vineyard blocks of Merlot on a farm in the vicinity of Somerset West. They studied the growth patterns, berry development and final wine of vineyards which occur in sheltered areas on the farm, which don't experience much wind influence. These were then compared with vineyards which are exposed to the prevailing winds of the area.

Windblown vines produced wines which had distinct plum characteristics while the sheltered vines tended to carry through pungent blackberry flavours to the finished product.

The simple explanation is this: a vine battered by wind will produce more lateral growth and result in a higher percentage of younger leaves in the canopy during the critical time of fruit ripening. Younger leaves will increase the acid content in the grape which ultimately deliver a different flavour in the final bottled wine.

Naturally the other aspects of terroir - soil type, slope aspect and microclimate - will remain significant drivers in the creation of a specific flavour profile. Certainly the rootstock and clone of each variety will continue as master crafters in your wine. But wind is no longer as mythical as before.

The research has yet to be written up and published, but it adds a whole new dimension to what winemakers have been claiming for years about the influence of sea breezes on their wines.

Leonie Joubert is a freelance science journalist with a special interest in climate related issues.

Soil is a significant driver in the creation of a specific flavour profile
Soil is a significant driver in the creation of a specific flavour profile

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