Wine 101: Minerality in wine explained

Flint. Chalk. Slate. Crushed rocks. Oyster shell. The aroma of standing next to a hot brick wall. It might sound more like memories of shovelling gravel (do we all have those? No?), but these rocky terms are genuine wine descriptors. If you’ve ever heard someone use the term ‘minerality’ in relation to wine, they’re talking about flavours and aromas like these ones. 

Sure, you’ll see it on riesling bottles and read it in wine reviews (and your enthusiastic wine friends will definitely pull it out at a tasting), but minerality isn’t always an intuitive term. Unlike, say, fruitiness, which is a more straightforward and understandable description, minerality is a little vague. It’s kind of like tasting and smelling rocks, stones and minerals, but it’s not 100% the same thing as tasting cherry flavours in your pinot noir. It's more like…well, you’ll see.

Like a pebble in your shoe, minerality can be annoyingly evasive – even wine legends like Jancis Robinson admit the term is elusive. At its most basic, minerality refers to a series of flavours and aromas that remind us of minerals and other characteristics that don’t really fit the categories on your flavour wheel like citrus, flowers and red fruits. It can also refer to the texture of a wine (the phrase ‘pebbly mouthfeel’ is a personal favourite), which makes things even more complicated. 

Typically, minerality gets pinned to the shirts of lean, crisp, high-acid, cool-climate white wines like Chablis or German riesling, but reds can be mineral, too. There’s plenty of debate about whether or not minerality is literally the flavour of minerals (more on that below) but, at the very least, the wine community seems to agree that minerality pops up in certain varieties and styles, and it can be an evocative way to describe or identify a wine.

If you were to lick a stone, would you get a better sense of minerality? Well, the jury’s out. There’s more than just literal flavour compounds in wine’s complicated chemical soup to trigger our association – we’re also tasting based on our own experiences and physiology, for example. This means that when we pull out fun-sounding flavours like forest floor or horse blanket, we’re using metaphor to help explain the experience of wine. The same applies to minerality. 

In this Word On The Grapevine piece, the author notes: “Perhaps when we describe riesling as smelling or tasting like slate, opposed to being literal, we may in fact be exploring and sharing our mind’s formulation of what we believe slate would taste like were it to have a taste.”

Minerality also tends to be perceived in those wines that lack primary fruit flavours and feature stronger acidity or similar characteristics. With that in mind, here are a few of the major mineral descriptors that, whether you’ve tasted talc or not, should be pretty understandable:

• Flint/gunflint: Steel and metal with a slightly smoky aroma, like a struck match or gunpowder smoke
• Petrichor: The smell of rain on hot stones
• Chalk: The aroma of blackboard chalk, sometimes perceived as textural, with a dry or powdery mouthfeel
• Slate, granite: More of a general wet stone taste and aroma
• Oyster shell: A savoury and slightly salty profile, sometimes with a chalky mouthfeel
• Steely: A metallic/mineral term that’s more about powerful, lean acidity than flavour as such
• Graphite: Remember the smell of sharpening an HB pencil? That’s it

This is the tricky question when it comes to minerality. It’s safe to say there’s a bunch of minerals present in vineyards, but there’s little consensus on whether those flavours are literally transferred into the wine. 

Alex Maltman, a geology professor and wine enthusiast, has dedicated plenty of time to the topic and found that, despite all the noise, we still don’t really know what gives wine these mineral characters. In one Decanter article, Alex writes: “If wine minerality was due to mineral nutrients, then it should be easy to enhance it by simply adding some more. But for various reasons it doesn’t work.” 

One possible explanation is that mineral flavours, aromas and textures are the result of other processes that end up providing a perception of minerality, but not as a result of actual minerals in the wine. Oyster shell minerality in Chablis, for instance, may be because of a selfish-like sulphur compound called methanethiol. 

It’s not satisfying, but the general conclusion from the experts is that, typically, we just can’t be sure about the causes of minerality.

We do, of course, know which wines show off minerality. Chablis is a stone-cold classic of the genre – a lean and bright French chardonnay that typically has mineral notes of briney oyster shell, steely acidity and a chalky texture. You’ll get similar mineral characters from Chablis’ compatriot Sancerre (a zippy, chalky sauvignon blanc) while other sauvs from Pouilly-Fumé are known for their notes of flinty gunsmoke.

German riesling is another for the mineral fans. These tend to demonstrate the acidic and textural side of minerality that can lead to some excellent descriptors like “sucking on a pebble” and “like moisture soaking into slate”. Australian riesling – often bone dry with zippy acidity – can show off mineral notes like talc, chalk and steely brightness.

Minerality is most commonly associated with white wine, but you’ll still find reds with these characters. Mostly, these are austere – a term that really just means more acid or tannin and less fruit – European wines like syrah from the Rhône in France. These wines can carry a blood-like iodine flavour, which is not actually a bad thing, while the mencia and grenache of Spain’s Bierzo and Priorat regions are known for their pencil-lead graphite aroma.