Elusive, indefinable, subtle, intangible, vague, mysterious, obscure, esoteric… these are all words that describe the inability to define or explain the concept of minerality in wine.

Webster’s dictionary defines the word ‘mineral’ as follows: “An inorganic species or substance occurring in nature, having a definite chemical composition and usually a distinct crystalline form.” But how does this translate to what is swirling around in your glass of wine? Instead of trying to explain how a chunk of soil ends up in your wine, I will try to focus on how it impacts the very essence of your wine experience.

The first time that I conclusively decided that minerality exists in wine, was in 2007, when I tasted a lovely barrel fermented Chardonnay from the Hemel and Aarde Valley in Hermanus, one of the most beautiful coastal towns in South Africa. As I was sipping this heavenly elixir, the winemaker was rambling on about terroir, soil types, racy acidity and minerality. He scooped up a handful of dirt and had me smell and even taste some of the smaller pebbles. It was right there and then that my mind and palate made the connection between what I was tasting and what the mineral debate was about. So-called wine pundits often use the term ‘minerality’ to describe a wine they’re unsure of, but in practical terms descriptors such as limestone, chalky, metal, flint, graphite, pencil lead and quartz are used.

I’ve experienced this phenomenon in South African and foreign wines e.g. Sauvignon blanc, Chardonnay, Riesling, Semillon, Pinot noir and even Cabernet Franc. I should add that red wines (as opposed to white wines) often lack distinct minerality as it is often masked by the more abundant phenolic and tannic compounds. Nowadays, my palate is more sophisticated and whether I drink a sublime Sauvignon blanc or a charming Chardonnay, I always first seek minerality, which makes my eyes haze over and conjures forth romantic images of rolling hills and soil teeming with potential. Next, I seek out those transient pockets of flintiness that dance on the edges of my tongue and which ever so often go hand in hand with racy, firm acidity. Why not try this: lick the poles of a small battery. This electrifying experience should leave you with a coppery or metallic taste in your mouth. If you can imagine greatly diminishing this effect, then you’re getting closer to ‘sol exprimé comme le liquide’ (soil expressed as liquid).

I think too much focus is being put on explaining single sources of minerality, as humans invariably tend to do. Synergy defines a situation where the sum is greater than the parts. Simply put, terroir, viticultural technique and winemaking style will all add together to yield a single product. A product, unimaginable in its chemical complexity, yet unfathomably single in its ability to please and unify humans all over the world.

Bernard Mocke is a technical consultant for Anchor Wine Yeast.