Teaching your Grandmother to Suck Stones

Passing down the wisdom of (perceived) minerality in wine is becoming increasingly suspect - even for dyed in the wool terroirists. No lesser being than Rhône-ranger Chapoutier has declared that ‘petrol’ characteristics are a winemaking fault saying they are a result of hard pressing of decomposed veins within the grape.

Comparing the debate over petrol aromas in Riesling to the issue of spoilage yeast Brettanomyces, Chapoutier said it is absurd that ‘historical defects in wine should be accepted as part of the character of the wine’ and that the vital aspect of Riesling vinification is the gentlest of pressings, often taking 12 hours, so as to avoid breakdown of the vascular structure within the grape. The Chapoutier family also make Riesling in Alsace and Victoria, Australia. 

Scientists are challenging the notion that terroir can be detected in a wine. As part of a study into vineyard soils, the Geological Society of America concluded that the French ‘gout de terroir’ - translated literally as 'taste of the soil' – probably isn't caused by minerals found in the vineyard.  'If wine lovers are going to talk about a mineral taste in wine, they should acknowledge that we don't at present know its cause”, says geologist Alex Maltman.

And they say the concentration of minerals in wine is below the threshold of human taste and smell. "I am not saying that chemistry and geology have no effect on the wine. It may have effects that we don't understand. But whatever 'minerality' in wine is, it is not the taste of vineyard minerals," said Maltman.

The argument that minerality is a product of mysticism, stones and established commercial interest is supported by the absence of hard scientific evidence. Renowned vineous academic Dr Seguin’s research found that the best terroirs covered extremely diverse soils, while the common themes are that none of the soils are very fertile, none suffered mineral deficiencies, and that these soils regulated water supply to the vines in such a way that it was nearly always just moderately sufficient.

The nod toward climate is that the greatest expression of terroir occurs when grape ripening is relatively slow, therefore late in the season, i.e. cooler climates.

While economists and statisticians are regarded with some scepticism for interpreting data for a pre-determined result, The Economic Journal found that terroir plays no part in the production of great wines. Two European academics – including a Frenchman whose whereabouts is now probably in question – collected data on environmental conditions and wine making techniques across the vineyards of Haut-Medoc, a classic example for terroirists, and concluded that wine making technologies, not terroir, determine the quality of wine.

The French claim that there is no good substitute for terroir looks at best highly exaggerated the professors said, at worst, terroir has no influence and the right combination of weather, vines, technology and chemistry are sufficient.

The irony – as all grandmothers now – is that soil minerals, in the right combination and concentration, are the only minerals that count. 

Jonathan Snashall