The appliance of science

It’s a current buzzword when talking about the characteristics of a wine, but what exactly is minerality? Sally Easton MW searches for a satisfactory scientific explanation

Minerality in wine is one of the trendiest tasting terms of our times. Science is establishing that it does exist, at least sensorially, but identifying potential responsible compounds or complex of compounds working in combination, and that can be chemically analysed, remains elusive at best.

No minerality directly from rock
Professor Alex Maltman of the Institute of Geography and Earth Sciences at the University of Wales, Aberystwyth explains that firstly, “there is a whole series of complicated ways in which the parent geological minerals decay to yield nutrient minerals”, and “for roots to pick up nutrient minerals, such as potassium and calcium, these elements have to get into solution.

Then there is a whole series of complicated ways of those elements getting into the vine roots – a series of distancing reactions between geological minerals and getting nutrients into the vine.

“When you start making wine, yeast takes some of those nutrients from the fermenting must, making the connection between mineral nutrients and geological minerals even more remote and complicated.”

He adds: “Whatever minerality is, it is not these elements that ultimately came from the vineyard. They’re last in all the things that give wine its flavour.”

With minerals comprising just 0.2% of wine, Maltman said you cannot taste the minerals, especially with all the organic compounds that do give wine its flavour.

Semantic confusion
Though, Maltman explains: “I’m not saying the taste attribute doesn’t exist in wine. But it’s given the label that gives a connotation of origin, of coming from vineyard. People used to talk of austere, lean, steely, even. As soon as people say minerality, people assume minerals are in the wine.”

To geologists minerals are complex compounds – collections of minerals and/or elements bonded together, such as feldspar. To nutritionists minerals are single elements – zinc, calcium, potassium. To wine people minerality seems to elicit a direct causal link with vineyard rocks despite this being an untenable thesis. All of which creates confusion: of description, of accuracy, of communication. This is not to say that soil, geology, drainage and water holding capacity are not important influences on the flavour of wine.

Which leads us back to minerality by association: “This is Mosel Riesling therefore I’m tasting slate” or “this is Sancerre therefore I’m tasting gunflint”.  Minerality has relatively quickly become a literal and emotive “beam me up Scotty” of rocky allusions which create vinous illusions.

Leave a Reply

Your email address will not be published. Required fields are marked *

Subscribe to our newsletters