For some it’s not even a word. It’s not in my dictionary. Yet few concepts in wine, not even terroir, excite the angry to expletives more than this harmless word can!
For some the idea that there’s a mineral quality in some wines, almost akin to those fruit flavours we find in tasting notes from Parker to Pigott, is proposterous. We see very long, learned, articles written by scientists explaining with just a hint of impatience that whilst wines may contain traces of compounds which mirror those in bananas, blackcurrants, linden and lovage, there is absolutely no way that the “soil to glass” transfer metaphor used so evocatively by Rhone expert John Livingstone-Learmonth can be literally true. Minerals exist in wine, but in a range from a few parts per million to parts per billion.
Yet the idea that we can taste something “mineral” in our wine still persists. A wine book written in 2014 contains the following, a description which paints a believable picture of a well tended patch of old vines in the middle of a sunny slope. The wines made from this idyllic plot:
“…tend to have a lovely salty minerality…as the vines are encouraged to cultivate deep roots that engage with the bedrock, processing its minerals through living soils”.
The most cited example of minerality in wine must be that of Chablis. Everyone knows that mouthfeel which makes Chablis so different to almost any other Chardonnay wine. It tastes nothing like a Puligny or a Meursault, or a Chardonnay from Napa or Marlborough. A good Chablis actually tastes as if they’d taken the fossilised sea creatures which make up the region’s soils, ground them into powder, and dissolved some in every vat.
It’s not just Chablis and its chalk. Volcanic soils often give wine a mineral flavour which, at its extreme, can smell like iron filings, or sometimes taste how we’d imagine wet terracotta might taste. Valpolicella, Etna Rosso and Marcillac from the Aveyron in France come into this category.
Then there’s Riesling, from the slate soils of the Mosel, Saar and Ruwer, where slate forms not just the bedrock, but litters the surface of the vineyards. Here, mineral geekery hits new heights as different types of slate are distinguished on the palate by experts. The non-expert is aided by the use of wine names such as Schieferterrasen and Vom Blauen Schiefer by Lower Mosel producer Reinhard Löwenstein (Heymann-Löwenstein). As Stuart Pigott (see below) says about Reinhard, he loves his slate, and is always quoting the Bob Dylan line, “everybody must get stoned”.
And whilst we’re in Germany, anyone who begins to appreciate Spätburgunder starts to identify those from the parts of the Ahr where it grows on slate and those from Baden’s Kaiserstuhl (volcanic), as opposed to the limestone of the Cote d’Or. To suggest that such differences have nothing to do with the soils and bedrock of each region, merely being the product of factors such as climate or winemaking challenge logic.
Some of you will already have noticed a big flaw in the narrative, especially those who read Alex Maltman’s article on wine and geology in World of Fine Wine this summer (WFW 48). Despite the quote above, about vine roots delving deep, it seems that vines may take most of their nutrients from the soil above the bedrock, and these soils often bear little relation to the underlying rock type. As Maltman says:
“By definition the bedrock is pretty much intact, apart from perhaps some fissures that may conserve supplementary water into which deep roots may tap: It is the overlying loose material, the soil, that is largely used for water and nutrition. And almost invariably, the age of the soil will be unrelated and vastly younger than the bedrock” (original itals).
Alex Maltman is Professor of Earth Sciences at Aberystwyth University in Wales, and he does get around on this subject. He’s the go-to guy for geology and wine. In a very good article written by Chris Simms in New Scientist (9 May 2015), entitled “Grape Expectations”, he reminds the author that despite minerality becoming a wine buzzword there is no known process by which vines take up minerals from the soil and transfer it to the wine. Furthermore, by and large, excepting sodium chloride, Maltman points out that minerals have no detectable taste.
Barry Smith, who specialises in the multisensory perception of flavour at the University of London’s School of Advanced Study, really puts us in our place in the same article. He tells Simms “The idea you can taste minerals from the soil is absolute rubbish”. How do we come back from that?
Well, I suggest two ways. Imagine first that you are on holiday in Aosta’s Valgrissenche and that you have purchased a bottle of the local white wine, Vin Blanc de Morgex et de La Salle. The co-operative’s Cuvée Rayon will do. You are on a nice walk up to the refuge called Mario Bezzi at the top of the valley. Half way up you stop for lunch, wedging the bottle in the icy stream that flows down from the dwindling glacial ice you will later navigate before reaching your goal. Sitting in the warm alpine sunshine, listening to the warning calls from a family of marmots on the other side of the valley, you uncork the bottle and sniff. It has a purity akin to Evian water with a light infusion of herbs. When you taste it…there’s something unique. To confirm your palate’s signals you take a small rounded stone from the stream and lick it. Exact match, the mouthfeel is identical.
But note, “mouthfeel”. What we have here is not the flavour of the pebble. The geologist will tell us that the pebble has no taste. It’s that feeling on the tongue and around the mouth. Mouthfeel is something we get from all wines. It can be oily in the case of a big Alsace Pinot Gris. It can come from the tannins in a young Pauillac. It can come from the acidity of a Franken Silvaner, or the sweetness and acidity of a Sauternes in a strong botrytis year. But wherever it comes from, the taste of that Blanc de Morgex can be described in no better way than “mineral”.
So if it isn’t actually minerals you are tasting, then what is it? We can look for explanations, but I don’t think there’s a definitive scientific one. In his 2014 book on Riesling, “Best White Wine on Earth”, Stuart Pigott has written a very good section on minerality and mouthfeel (pp 34-39). He talks about potassium, one of the minerals present in wine, working with the wine’s acidity to give a salty minerality. He mentions sulphurous compounds created during or after fermentation, and there are other choices made at the time of fermentation which may come into play, such as yeasts. But at the end of the day, his following quotation sums up my feelings as well:
“A lot of nonsense is talked about the mineral taste of wine, which is a real part of Riesling, but also rather mysterious”.
My own view is that science may provide the answers in the future as to why wines sometimes taste in a way which encourages us, we just can’t help ourselves, to use the term “minerality”. But to be honest, I don’t think it matters one bit. You see, what is minerality but a perfect metaphor for what we are tasting in a Chablis, a Wehlener or an Etna Rosso.
What is the point of a tasting note? It’s not really there to provide a technical analysis of the chemical composition of the wine in the glass. It’s there to paint a picture of a vibrant, living thing which can thrill our senses of smell and taste like few other forms of nourishment. Wine is there to feed the soul as well. It may sound pathetic, but who reading this hasn’t taken one sniff of a wine and found themselves transported to a heaven of sensual pleasure and, if lucky, a profound recollection of their previous encounter with that scent and taste, a true Proustian moment. Wine, in this respect, has the power to be transformational.
All we want from someone else’s description of a wine is a sense of that experience summed up in a few crafted phrases. A picture painted in vivid colours. I think that the term “minerality” on these occasions conveys, as a metaphor, something that we all understand. And for those lucky enough to have climbed the slopes of the Doctor above Bernkastel, or Achleiten on the Danube, to have walked the Grand Crus of Chablis, or to have driven in search of the lost vineyards of Marcillac among the wooded hills south of Conques, it’s a word capable of transporting us back to those places.
To those able to understand a metaphor, minerality conveys the essence of something very real. But it is just that, a metaphor, so let’s remember that when we see it used in a tasting note.