The minerality in wines
- Monday 9 June 2008
Wine critic Robert Parker describes a white Hermitage as having ‘stupendous aromas…of a liqueur of stones’. Stephen Tanzer writes about the ‘uncompromising aromas…of powdered stone’ in an Alsatian Riesling. Decanter describes a 2005 premier cru Chablis as having a ‘wet stone nose’ and ‘mineral-laden structure’. What are they talking about?
They will tell you they are trying to describe an ineffable quality which can
be found in a wine’s aroma, but also in its taste, where it may also be called flinty, chalky, or gravelly. It is particularly noticeable in high-acid whites such as Chablis and Sancerre, Mosel and Alsatian Rieslings, and Austrian white wines. But terms like ‘flinty’ and ‘crushed rock’ are metaphors. So what exactly is minerality? Is it scientifically defined? The Oxford Companion to Wine is silent on this aspect of the aroma and flavour of wine, although it does describe the mineral elements that can be found in wines, such as potassium, sulphur, copper and zinc. But the presence of these elements doesn’t seem related
to what wine aficionados would describe as minerality. Dr Ann Noble’s famous Wine Aroma Wheel also has no slot for minerality. This, she says, is because there are no specific compounds in wine that can be linked to the stony flavours or aromas we think of as mineral. ‘I think minerality might come from a complex of sulphur compounds found naturally in the grapes – not the sulphites added as preservative,’ says Dr Hildegarde Heymann, a professor of enology at UC Davis who specialises in the descriptive analysis of wine. ‘But I have no scientific basis for saying this.’ The term has no reference to any specific compounds, or any proven basis in science – at least not yet.
Though it’s a word she uses with care, minerality is obviously a perception she
grasps, for she believes age does affect minerality in wine. ‘It seems like wine can lose some of this mineral character over time. Sulphite compounds are very reactive in wines as they age,’ she says. But such is the state of science regarding minerality that Heymann immediately qualifies her
statement again: ‘I have no scientific basis for saying this.’ The concept is even more slippery for Dr Susan Ebeler, professor of viticulture and enology at UC Davis and a specialist in wine analysis and sensory chemistry. 'It’s a perception people have,’ she says, ‘but it may not be specific compounds
that produce it. Is it in the alcohol, in the salts? There’s no clear answer. Maybe it’s simply subjective. For it to be objective, we need a reference standard so people always can say, “That’s minerality!” when they encounter it. But we’re not there yet.’ Elusive concept Winemakers in the US are reluctant to
use the term – perhaps because it is so subjective – and yet they seem to
appreciate just what it means. ‘I don’t use “minerality” in describing my wines,’ says Richard Arrowood of Arrowood Vineyards and Winery in Glen Ellen, Sonoma County.
But that doesn’t mean he’s not aware of it. ‘Minerality to me is like when you put stones in yourmouth as a kid – there’s a subtle taste. It’s stony or flinty, a combination of clean earth and rock. You find it in Chablis and Meursault, but it’s not scientific. I have no idea where it comes from.’ At Geyser Peak Winery in northern Sonoma County the wines are more fruit-driven. Winemaker Mick Schroeter says: ‘Minerality is not a term we use often at Geyser Peak. When we do, it’s usually to describe Sauvignon Blanc. It would also apply to Pinot Gris and white Burgundy. ‘I see it as a character on the nose or palate like the smell of wet stones, wet gravel or wet pavement. It may also be likened to the soils the grapes are grown in and the impact those soils have on the character of the wine – for instance, calcareous soils in Burgundy.’ Cellarmaster Jacques Lardière of Burgundy’s Maison Louis Jadot agrees with Schroeter. ‘All our wines carry minerality,’ he says, pointing out that microorganisms in the soil cause minerals in the bedrock to dissolve in the water in the soil, which the vines then absorb. ‘This minerality applies to both Chardonnay and Pinot Noir because their
fruit depends on the same bedrock.’
He explains that the minerals in the soils of Burgundy create coherence in
Burgundian wines, from the least to the greatest cuvées. ‘But,’ he adds, ‘there exist vineyards which are able to reveal this de-mineralisation with more dynamism.’ All of which places the concept of minerality squarely back in the area of terroir for this French winemaker –exactly what one would expect in France, where ‘minerality’ is less a metaphor for a stony flavour than the contribution of soil’s minerals to the overall success of a wine. The term is in vogue now in the UK and US. People may not know precisely
what it means but, like the Cheshire cat, they’re pretty sure it’s there, because of that lingering grin.