This is another article on minerality… I wrote my first piece about this topic more than 15 years ago and have been asked by a lot of other writers to write many others since then. Minerality in wine has been the subject of conferences, masterclasses, workshops, etc., for years. What is it that makes this topic so fascinating?
It may have to do with the blending of the pragmatic usefulness – evoking the much-loved connection between wine and land – along with the continued lack of consensus as to what the term means.
Minerality is not just a wine word. It is also reported in beef, watercress, and maple sugar.
Minerality: Identifying and reporting it
How do we feel it first? The answer is that it varies. According to a recent study, 16% of wine professionals detected the minerality by smell and 20% by taste, while the rest used both senses. All three groups differed in their assessment of the intensity of minerality and described it differently.
In the nose-clipped condition, about the same percentage correlated acidity and bitterness with minerality. A second study concluded that French tasters rely more on smells than New Zealanders, who tend to use their nose and palate.
In other studies, it was found that when both taste and smell are used, the acidity is more important. However, if only scent is used, then the variety matters most. Which grapes are more likely to have minerality?
The University of La Rioja in Spain conducted a study on red wines made of Tempranillo and Syrah and found inconsistent responses. Minerality, however, is mainly associated with white wine, although there is disagreement about the specific varietals.
A study conducted at UC Davis in California found that Rieslings, Pinot Gris, and Sauvignon Blancs were more mineral-rich than Chardonnays. It’s important to note that this study included Chablis – the “archetypal mineral wine” for many.
The majority of vines, however, are grafted. It is the rootstock, rather than the cultivar, that interacts with soil. I am not aware of any studies that evaluate the role of roots in minerality.
How will you explain to others what it is you are sensing?
The words that people use to describe minerality have been grouped into several categories. These include acidity, freshness, and tenseness. Other categories include seaside-related words like iodine, sal,tiness, and shellfish.
Minerality is a positive attribute for winemakers, as opposed to the negative connotations of some consumers.
The different word associations found by researchers at UC Davis in California and Lincoln University, New Zealand, are another example of the communication issue. Both teams found positive correlations with words such as citrus, freshness, zingy, and smoky. However, Lincoln’s researchers did not find any correspondences with acidity or reductive tones.
A study found that Swiss wine drinkers used a broader and more specific vocabulary when describing minerality. One experiment revealed that the language used to describe minerality was dependent on the knowledge level. The most inexperienced participants had never heard of it, while the experts were more interested in acidity, terroir, and earthy flavors.
What is minerality in wine due to?
It is not surprising that scientists continue to struggle to identify the components of a wine that might trigger the perception we call’ minerality.’ The majority of studies have focused on possible roles such as acidity, reductive sulfur compounds, and lack of fruit.
In the early studies on Italian Rieslings and Gruner Veltliners, in particular, the acidity was attributed to a weak, slightly salty-tasting succinic acid. However, this suggestion has not been proven.
UC Davis reported in a later study that professional tasters detected minerality in wine with higher malic, tartaric, and free sulfur dioxide levels. A New Zealand study found that sulfur oxide played a significant role in the perception of minerality.
However, several studies have indicated that sulfur compounds such as polysulphanes and methanethiols are relevant. A Swiss team, in their quest to better understand the world, was studying toilet malodours. Yes, toilet malodours. They isolated an ‘odour like flint’ and found it was caused by hydrogen disulphane or HSSH. The Swiss team then discovered that the wines that had the most minerality in the blind tastings contained more HSSH.
In the absence of a definitive relationship, studies have not been able to confirm a link between minerality and reductive phenomena.
Chemical analysis has also not supported the perception of minerals in wines due to a lack of flavors. The lack of key aromatic components in Sauvignon Blanc (e.g., thiols, isobutyl pyrazine, and isobutyl methyl methoxypyrazine), for example, does not correlate with perceived minerality.