Posted byLidija BiroPosted inGrape varieties, WineTags:cool climate wines, minerality, wine education, wine tasting
Have you noticed the proliferation of wine tasting notes that mention minerality?
So, what does that actually mean, since rocks and minerals have no aroma or flavour?
Moreover, minerality in wine has not been substantiated by chemical analysis. Alex Maltman, a geologist and professor emeritus of earth sciences at Aberystwyth University in Wales, studied the chemistry of vines and minerals and how they interact. Professor Maltman concluded that it’s not possible for us to taste minerals from the soil when we drink wine.
Also important: Most vines are grafted onto a different rootstock … and this rootstock – not the grapevine variety/cultivar – is in contact with soil minerals.
Yet winemakers, viticulturists and wine reviewers/writers continue to find a correlation between certain wines and mineral rich soil types that produce them. Those encompass limestone, chalk, slate, silex (silica based flint), schist, gravel, granite, gneiss, Kimmeridgian (a combination of limestone, clay, and fossilized sea shells), and volcanic soils which are found in many wine regions of the world.
That is a conundrum and the motivation behind this blog. I am trying to understandwhich wines are described as having minerality and what is actually perceived on one’s palate.
First, let’s be clear about the process of tasting wine or anything else. Everybody’s palate is different because it depends on chemical interactions of a food or wine with the chemistry found in the mouth of an individual, her/his health and age.
Your ability to taste comes from tiny molecules released when you chew, drink, or digest food; these molecules stimulate special sensory cells in the mouth and throat. These taste cells, or gustatory cells, are clustered within the taste buds of the tongue and roof of the mouth, and along the lining of the throat. Many of the small bumps on the tip of your tongue contain taste buds. When the taste cells are stimulated, they send messages through three specialized taste nerves to the brain, where specific tastes are identified. Taste cells have receptors that respond to one of at least five basic taste qualities: sweet, sour, bitter, salty, and umami (savoury). Another chemosensory mechanism, called the common chemical sense, involves thousands of nerve endings, especially on the moist surfaces of the eyes, nose, mouth, and throat. When you eat, the sensations from the five taste qualities, together with the sensations from the common chemical sense and the sensations of heat, cold, and texture, combine with a food’s aroma to produce a perception of flavour. Source: https://www.nidcd.nih.gov/health/taste-disorders
This idea of perception of flavour is key! Thus when describing aromas and flavours in wine, producers, marketers, and writers/critics are really using metaphors, mental associations, and recollections of past encounters with certain food and drink. The wine tastes of white flowers and ripe apricots – certainly no flowers or other fruit went into the making of the wine.
So back to the perception of minerality.
Wines that often carry the perception of minerality are cool climate whites (there are a few red wines, too, but more about that later). It has been suggested that 5 factors correlate with perception of minerality:
- the absence of overt fruity flavour in wine;
- higher levels of acidity;
- reductive wine making and the addition of SO2 (sulphur dioxide or sulphites – SO2 is added to wine in order to provide microbiological stability and to prevent oxidation);
- chemical compounds (mostly volatile sulfur compounds) occuring during wine fermentation such as BMT (benzenemethanethiol) producing stony/smoky notes; ethyl mercaptan (at lower levels) producing a burnt match aroma; methanethiol which has a shellfish aroma; hydrogen disulphane or HSSH that has a flinty note;
- and succinic acid (occuring during alcoholic fermentation), producing saltiness.
Let’s explore this a bit further …
White wines often associated with minerality may have some citrus notes but fewer ripe apple, pear, and peach aromas and flavours. At most one can identify lemon, lime zest, and grapefruit pith. These wines also have elevated levels of acidity that cleanse the palate, leave a deliciously tangy, cool, tactile sensation on your tongue, and a desire for more.
This tactile sensation or texture is usually present with wines that are perceived as mineral according to a teacher of mine and sommelier supremo, Peter Rod.
Clue words for minerality: textured, salty/saline/ocean breeze, herbal/herbaceous, earthy, wet stone, flinty, chalky, smoky, burnt match, gun flint, slate, stony, steely, umami, savoury, nutty, bitter …
Today’s wine making techniques may also contribute to the perception of minerality.
- higher hygiene standards,
- the use of stainless steel tanks,
- refrigerated transport of grape harvests from vineyard to winery,
- reductive winemaking (limiting or completely excluding oxygen and often resulting in detectable volatile suphur compounds or suphur flavours – some undesirable like hydrogen sulfide (rotten eggs) and some desirable like thiols – within limits – and those listed above),
- low temperature fermentation,
- cooling jackets on tanks
- and screw caps on wine bottles all might play a role.
Grape varieties also play a role in the perception of minerality – so what are the less fruity varietals and what should the wine consumer perceive?
| Grape Variety/Wine | Minerality Descriptor |
|---|---|
| Arneis (Piemonte, Italy) | – crushed limestone, textured |
| Assyrtiko (Santorini, Greece) | – flint, saline, textured, talc, clay |
| Chardonnay (specifically Chablis, France) | – chalk – struck match, gun flint – petrichor [which means the scent produced when rain falls on dry soil] |
| Chasselas (Switzerland) | – flint |
| Etna whites (Sicily): Cataratto, Carricante, Grillo | – flinty, smoky, salty, textured |
| Friulano (or Sauvignonasse, Friuli-Venezia Giulia, Italy) | – crushed gravel |
| Gavi di Gavi (Cortese grape, Piemonte, Italy ) | – herbal, savoury, wet stone, bitter |
| Grüner Veltliner (mostly Austria) | – ‘mineral core’, earthy, herbal |
| Falanghina (Campania, Italy) Fiano di Avelino (Campania, Italy) Greco Di Tufo (Campania, Italy) | – textured, stony, herbal, earthy, nutty, slightly bitter tannic finish, ‘rich minerality’ |
| Muscadet (Melon de Bourgogne grape, Loire Valley, France) | – saline, ocean breeze, sea shell/shellfish |
| Pinot Gris/Grigio (especially from alpine regions of Italy – Valle d’Aosta, Alto Adige, IGT Dolomite) | – smoky, savoury |
| Pouilly-Fumé (Sauvignon Blanc from Loire Valley, France) | – struck match, gun flint, smoky |
| Ribolla Gialla (Friuli-Venezia Giulia, Italy) | – textured, herbal/herbaceous |
| Riesling | – wet stone, slate |
| Sancerre (Sauvignon Blanc from Loire Valley, France) | – struck match, gun flint |
| Sémillon | – saline |
| Soave (Garganega grape, Veneto, Italy) | – salty, herbal, green almond bitter finish |
| Verdicchio (Marche, Italy) | – saline, savoury herbal notes |
| Vermentino (Liguria/Sardegna, Italy) | – crushed rock, citrus zest, slight bitterness on finish |
| Vernaccia (Toscana, Italy) | – saline, herbal, bitter |
Red wines with minerality: Far fewer red wines are described as ‘minerally’. But
reduction prone varieties such as Syrah, Mencia, and Carignan could qualify as having some mineral notes. For Syrah they tend to include cold stone, mixed gravel, limestone, shale, forest floor, and smoke. For Mencia, crushed gravel, and for Carignan, umami/cured meat aromas and flavours apply.
By coincidence, Christopher Waters, another one of my former teachers (and now writer colleague) recently posted an article in the Globe & Mail newspaper about minerality in wine … please read.
I hope you found this informative and that it has given you more understanding about what is meant by minerality in wine. Research and the science behind wine aromas and flavours continues to evolve … so stay tuned.
Which wines do you find ‘minerally’? Please let me know.
Cheers!