What is the M-word? Met him pike hoses? Oh rocks. And one nerd-point if you identify that.
No, ‘M’ as in, ‘mineral’. The organoleptic experience named mineral, or, minerality. The qualia of mineral.
Fact 1: minerals are rarely volatile at room temperature. Meaning, they do not evaporate, so, in fact, their propensity to smell is very small.
Fact 2: minerals are rarely soluble in saliva; few, if any, minerals are soluble in slightly acidic liquids. Meaning, they deliver little, if any, taste to wines directly.
Ascribing properties in an irrational way to wines is ubiquitous and I would admit to being a perpetrator. How about, “the smell of white flowers”? “Taste of yellow fruit”? Or white fruit, for that matter. Yellow fruit, yes, bananas, plums (yellow plums), pineapples (if you cut them open, that is). White fruit? None comes to mind, except, oh yes, white mulberries, which taste very much like red mulberries, and white currants, amazingly similar in taste to red currants. Then, there are white peaches, quite distinct from yellow peaches, but, also distinct from white mulberries.
I remember that the petroleum aromas of certain Rieslings, particularly late harvested, and wines with cellar age, and Australian ones, used to be explained as deriving from the slate, or shale. In the German, Mosel, vineyards, you understand. That it came directly from the slate, and slate was needed for it to develop. Now, have you sniffed slate? With the possible exception of certain petroleum carrying slate ore, slate does not smell of petroleum. Today, the origin of the petroleum aroma is known to be an organic molecule deriving from the skin of the grape. It has nothing to do with slate/shale/schist. Some of the best Riesling grows on the shale, that is true, but, I do not dislike Riesling from GC Brand, which is granite.
German Riesling are still fabulous when they are good.
Next, flint. In French, silex, or, pierre-a-fusil. Mentioned with Pouilly-Fumée, the East side sauvignon blanc of upstream Loire. Strike a piece of gun flint with steel (or a SECOND piece of flint), to get a spark, to start a fire or, to fire an old 18th century rifle. You may perceive a fleeting olfactorial sensation, it even stings the nose, briefly. Some of the best vineyards, on both sides of the Loire, contain flint – it may be written on the label (‘Silex’). So, does not light gun flint aroma present in some Loire SB obviously derive from the flint? No, apparently not. And flint, on its own, does not smell, nor taste (I refer to facts #1 & 2, above). The ‘gun smoke’ aroma is identified as being at least partly derived from a Sulphur containing organic compound, benzyl mercaptan, which is not normally found in flint. It is, on a sidenote, interesting to what degree compounds that in other circumstances smell absolutely vile, in small amounts (we are talking seriously small amounts here) will be delightful and add harmony to a product.
Onwards and downwards. Chablis. One of my absolute favorites. Young and perky, old and wisdom inspiring, I love Chablis when it is good. I remember somebody likening the impression given by Chablis to, “licking a blade of stainless steel”. Could have been early 90s? Well, yes, but, what does stainless steel taste and smell like? Obviously nothing! It does give a definite sensation, licking a steel blade, but it does not TASTE of anything (except if you get some kind of voltaic reaction from the fillings in your teeth, which would be unpleasant). Yet, Chablis is one of the wines most often ascribed ‘mineral’ characters – both in smell (“on the nose”) and in the mouth (“on the palate”).
Hugh Johnson, in a book I have misplaced somewhere, hypothesized that the ‘mineral’ character in Chablis might be some compound resulting from an in-bottle reaction between the added SO2 and other molecules present. I have so far not found any support for this hypothesis, though.
Succinic acid, and derived substances, exist in wines. The acid is present in maturing grapes, but the concentration falls and is very low by harvest time – most succinic acid and succinates appear as a by-product of alcoholic fermentation. The succinate ion has been implicated in the mineral aroma and, there is an article citing blind tasting of wine, spiked with varying amounts of sodium succinate. The wines were either Italian Riesling (a k a Welschriesling) or Grüner Veltliner, and the tasters were very well able to discriminate between the various concentrations of the addition. The description of the ‘spiked’ wines were “vinous, sapid, salty and sometimes even bitter.” The word, conspicuous by its absence, most interesting is of course ‘mineral’. They are not considered ‘mineral’. The terms vinous and sapid could perhaps be assigned to a taste enhancer, but, salty and bitter are both true tastes, not aromas, and, the sodium succinate is odorless – so in no way could it be considered the mediator of a “minerality on the nose”. Too bad – succinate is a compound that would appear to be “terroir driven”, as the concentration is dependent on the vine’s access to nitrogen compounds – a poorer soil (in terms of nitrogen) will, if I understand this correctly, lead to a higher concentration of succinate, all else being equal. Succinic acid also yields two esthers with ethanol, both of which are organoleptically active, yielding discreetly fruity aromas (apple), and, according to one commercial site, adds to the feeling of fatness in the wine (does this in any way correspond to the Italian ‘sapidità’?). Let’s not forget succinic acid – I will get back to it.
Back with some more boring stuff forthwith.