In this personal exploration of minerality I started here with a look at how rock minerals, such as feldspar (an important constituent of slate, gneiss, and countless other familiar rock types) might be transported into the root and then up to the fruit, giving us a fabulously mineral sensation when drinking the wine. My conclusion, in short, was that such a concept is nonsense
but
There was, however, a tantalising result for kaolinite (a clay mineral) and gibbsite (a form of aluminium hydroxide), both of which may form in the wine depending on the pH, or possibly even in the mouth under the influence of the much higher pH of saliva compared to the wine. There was a strong correlation between these compounds and the perception of minerality in the wine.
I clearly get minerality in many white wines. For me, the closest thing is the smell of a rain shower after a long dry spell.
“However, the finding that minerality might be engendered by the creation of minerals in a higher-pH, less acidic milieu seems at odds with the general perception that it is the acidic, cool-climate wines that are more likely to display minerality.”
I am not a scientist, and don’t believe that minerals or other components of the soil are sucked into the grapes thru the roots/vines. That doesn’t mean that it can’t become a component of the wine in other ways. The pronounced eucalyptus note in Heitz Martha’s certainly comes from the eucalyptus trees that surround the vineyard, either thru aromas that bind to the grapes, or mor likely, from some eucalyptus leaves that make it into the fermenters, intentionally or not.
Similarly, dust/minerals from the soil could quite conceivably coat the grapes and become part of the wine.
Wines are often/sometimes described as Earthy. Yet I don’t see anyone assuming that earth has been transported up through the roots directly to the grapes. And I don’t see anyone arguing that this is clearly impossible, so they wines must not smell/taste earthy (not saying anyone here is saying this, but it’s a common statement/implication of this argument).
Why do we all have a bee in our bonnet about minerality?
Aside from that, Chris Kissack’s article is very interesting. One minor point: he says, other than carbon, hydrogen and oxygen, all other nutrients come from the roots. But the leaves can directly absorb nutrients…foliar fertilization (spraying fertilizers, compost tea for example, directly on the leaves) takes advantage of this.
Chris - Kissack is right. It’s basic biology. The fact that a plant is growing in some dirt doesn’t mean that everything in that dirt is willy-nilly transported up into the fruit. Wine writers talk about minerality - biologists and botanists don’t.
First, there isn’t a tube that goes from the ground into the grape. The way things get into the grape is very complicated. Second, plants selectively absorb what they they don’t just take whatever is there, or they’d be dying left and right. Third, people need to define what “minerals” are in the first place.
What people are actually experiencing is probably a type of acid, like malic acid as opposed to another acid. It doesn’t have a fruity sense about it and makes people think of what a “mineral” would be like, so they use it as a description, but it’s illustrated in the line below, which, other than being a non-sequitur, is usually the way “minerality” is defined.
“However, the finding that minerality might be engendered by the creation of minerals in a higher-pH, less acidic milieu seems at odds with the general perception that it is the acidic, cool-climate wines that are more likely to display minerality.”