The word ‘minerality’ appears quite often in tasting notes and descriptions of wines. By some estimates, in as much as 10 per cent of descriptions. Sometimes to the irritation of professionals, as it remains a difficult concept to define without a scientific basis. Yet we too often describe wine as mineral. Especially the wines from Chablis. Minerality is attributed to the soil on which the grapes grow. As an expression of the terroir. Winemakers therefore look for minerality.
Minerality
For many wine lovers, the term minerality refers to aromas and flavours reminiscent of rocks, chalk, flint, wet stones or salty accents. Minerality is often associated with wines from specific terroirs. Minerality is therefore a sought-after effect. The flavours are not directly caused by the minerals in the soil the grapes grow on, but rather by the interaction during the fermentation process. Soils with more oxygen, water and nutrition contain more life. It strongly seems that these soils give minerality to wine. At least, what is considered minerality.
Geologist Alex Maltman states the following in the Journal of Wine Research (“Minerality in wine: a geological perspective” 2013): “Whatever minerality is, it cannot literally be the flavour of minerals in the rocks and soils of the vineyard.” Maltman explains that rocks consist of insoluble geological minerals, pointing out that all rocks are rich in minerals. However, grapevines absorb dissolved nutrient minerals, which originate from geological minerals. “There is no direct link between the taste of wine and the geological minerals in the rocks or the mineral elements in the soil. In any case, the minerals in wine are below the threshold of sensory perception”. In total, a wine contains a maximum of 4 grams of minerals.
Expressions of minerality
Minerality can manifest itself in the smell and taste of wine. For example, it can have a ‘flinty’ (flint) aroma or smell like wet stones after a rain. This is often observed in dry white wines, such as a Chablis. Besides the aroma and flavour, minerality can also relate to the structure of wine. Wines with high acidity and low alcohol content often have a ‘crispy’ feel on the tongue, which is associated with minerality.
Winemakers can therefore play with the vinification process to promote minerality. High acidity and low alcohol are among the winemaker’s handles. Minerality can be ‘just produced’. Winemakers try to make their wines in such a way that they reflect the ultimate expression of the terroir. At least, that is often the goal. Minerality is thus inextricably linked to terroir, but also to what a winemaker uses as a reference.
Scepticism
So minerality is actually a perception. Certainly from a scientific perspective, the word is approached with scepticism. In fact, there is currently no scientific evidence that minerals in the soil directly influence the flavour of wine. Instead, it may come from factors such as acidity, fermentation processes and other chemical interactions (sources: Tasting Table and Wine Enthusiast). But minerality remains a popular characteristic in wine. It is often seen as a sign of refinement and terroir, despite the lack of a clear definition.