Minerality or Electicity? Moving beyond matter towards energy in Wine.
Some time ago, I read an article that lodged itself in my mind, subconsciously attaching to other ideas until it gathered enough mass to warrant this deep dive.
The article challenges the notion of "minerality" in wine and proposes adopting "electric" instead. It cites several wine professionals, among them the highly regarded Raj Parr. The idea is that minerality isn't a flavor or aroma but an "energy" sensed in the wine.
Though we are tempted to credit this idea to high-profile wine expert types, this idea of minerality being electric can be traced back to Clark Smith in 2010; "It is an energetic buzz in the wine's finish, almost like an electrical current running through the throat…".
Minerality and Composition
The idea that minerals in the soil make their way into wines, giving them mineral characters, is so lacking in evidence that it won't be considered a plausible explanation for "minerality" in wine.
Many articles show relationships between "minerality" and specific Sulfur-containing compounds. One study investigated Chablis wines from the "left" and "right" banks. Left-bank wines are often associated with "minerality" more than those from the Right. Left bank wines had higher levels of methanethiol, a sulfur-containing compound implicated in "shellfish" fish aromas.
Other studies have implicated polysulphanes as the source of flinty, gunpowder, and match aromas.
However, the review concludes that the "…physico-chemical drivers of perceived mineral character in wine do not have a simple explanation."
The drive to explain minerality as a function of a wine's composition makes perfect sense, given the most accepted explanation for how taste and smell work: Shape.
Smell and Taste Receptors recognize Shape
Our sensory organs begin as receptors capable of sensing environmental conditions. Your skin is capable of sensing pressure and changes in temperature. Your eye contains receptors activated by light and specific colors.
It is assumed that Taste and smell are based on receptors activated by specific molecules. What keeps the scent of cedar from activating receptors for the smell of roses? The specificity of a receptor is based on its physical configuration, which is capable of binding with a molecule based on its shape. The Shape of the compound that is the source of the smell of cedar doesn't have a shape that activates the receptor for the scent of roses.
If we subscribe to the explanation that the shape of a compound is the source of activity on a receptor, it makes perfect sense to focus on a wine's composition as its source of minerality.
Given the affinity winemakers have for composition; pH, TA, Malic Acid, Tartaric Acid, Ammonia, Tannins, Phenols, Glucose, Fructose, and alcohol it is surprising that anyone would even consider suggesting an "energy" as part of a wine's sensory profile. We tend to be chemists more so than physicists.
Soil Microbiology
Clark Smith suggests that "excellent minerality can be obtained on any site if living soil principals are applied ." He cites the work of famed French Soil Scientist Claude Bourguignon, who in some circles is credited with saving the terroir of Burgundy, suggesting that mycorrhizal fungi will facilitate mineral uptake by a vine by expanding its rootlet surface a hundredfold".
Clark then goes on to suggest that like "the perception of acidity is due to the flow of protons (hydrogen ions) discharging from binding sites on weak acids," that minerality could be "a flow of electrons released from various elements of the periodic table as they move to higher valences."
However, this ultimately leads to an explanation based on composition. Living soils, namely Mycorrhizal fungi, serve as extensions of root systems and increase the ability of vines to take up minerals. Yet we don't see compelling evidence that these minerals are the source of minerality.
However, once we get below the level of individual atoms, such as electrons, reliance on the "shape" model becomes much more problematic.
So, all of the above discussion has been an extremely brief and over-simplified explanation of the challenge of getting to an explanation of an energetic sensation, as suggested by Raj Parr (in the Wine Enthusiast article cited above) and Clark Smith, based on composition.
Redox Potential
Winemakers and enologists are sometimes poor scientists due to their limited frame of reference for widely-ranging phenomena. Redox Potential is perhaps the best example of this. Ask any winemaker about "reduction," and you will get a discussion of Sulfur compounds (note how Sulfur is mentioned again) and "stinky wines ." Oxidation will be treated as aromas dominated by oxygen-containing compounds like aldehydes.
However, if we remove ourselves from the discussion of enology, we find reduction and oxidation are energetic states that occupy the extremes of a spectrum. For something to be reduced, something else needs to be oxidized. At its most fundamental level, it describes the movement of electrons (note Clark's comments above).
Though winemakers classify wines as reduced or oxidative based on the relative levels of specific molecules, the presence of those molecules reflects the wine's energetic state concerning redox potential. (There may well be other energetic states besides redox potential, thus the precise language used here).
““... winemakers should be thinking less about the presence or absence of compounds associated with “reduction” or “oxidation in their efforts to make wines with (or without) “minerality.””
The Renaissance Man and Perfume
This discussion of minerality as an energetic sensation reaches deep into my brain and pulls out a seemingly unrelated source.
The Emeror of Scent: A True Story of Perfume and Obsession chronicles the work of biophysicist and perfume aficionado Luca Turin. Turin noticed a fundamental problem with the "shape" model of scent. He noted that compounds containing Sulfur always retained some signature of Sulfur regardless of the rest of the molecule. The molecule's shape would be dramatically different in each case, yet the smell of Sulfur persisted in each. He pivoted his scientific work to examine this issue.
After a series of investigations, he concluded that scent wasn't a function of the Shape of a molecule but of the energy of the bonds in the molecule. However, the theory lacked a receptor capable of doing this. Until he came across some work on a class of proteins known as G-proteins. It was suggested that these proteins were capable of sensing energy.
(Though the book is a fascinating read, I should point out that Luca Turin's theory was never widely accepted in the sensory community)
The Takeaways for Winemakers
At last, I am getting to a point.
Wine experts are suggesting that the descriptor "minerality" be abandoned. They recommend replacing it with something more attributable to an energetic state, namely electricity.
Studies attempting to elucidate the chemical source of minerality often point to Sulfur-containing compounds. The presence of these Sulfur-containing compounds is likely a reflection of the underlying redox potential of the wine.
Raj Parr and Clark Smith, a decade before him, suggest that a sensory attribute is perceived as an energy and not a specific flavor or aromatic.
I am suggesting that the perception of minerality is, in fact, the perception of an energetic state. I am further suggesting that minerality is not caused by compounds shown to correlate with its expression but that those compounds and the sensation of minerality indicate the wine's redox potential. Furthermore, I suggest the possibility that perception of this energetic state is through a sensory pathway separate from that used for Taste and smell.
At its most applicable level, winemakers should be thinking less about the presence or absence of compounds associated with "reduction" or "oxidation in their efforts to make wines with (or without) "minerality." Instead, they should be thinking about how farming and winemaking practices impact the wine's energetic state and its redox potential that precedes the appearance or disappearance of reductive or oxidative compounds.
The focus on these compounds, as lagging indicators of the underlying energetic state, only allows a winemaker to be reactive instead of proactive.