Have you heard the word “petrichor”? Lovely – the smell of rain on the ground after a drought. The word was invented in Australia in the early 60s. The word is constructed from the words for stone (petra) and the blood of the Greek god (ichor), so, “rock blood”. The smell stems from vegetable oils, exuded from plants, plus a substance called geosmin that stems from bacteriae. I could imagine a vineyard somewhere in the Nahe with a name like that (but in German, of course). “Steinblut” or “Felsenblut” … just a slight digression.
My previous blogpost caused some commentaries from two guys whose opinions I value very much.
Mike Tommasi: ” I would distinguish ”mineral aromas” (like riesling) from ”minerality”. If anything because the former is easily described. The latter, elusive as it is, seems to be mostly found in northern whites, mainly Loire and Burgundy, even Champagne. I suspect it is merely… salinity.”
Yes, quite so. Mineral in the nose and mineral in the mouth could be quite different things. I therefore re-read the latest entries in Guide Hachette, sticking to 2016 (because there were the most entries of wines considered ‘mineral’), adding the Alsace Rieslings of the same year.
Here, ‘M’ stands for total number of mineral wines, C/PC are Chablis combined with Petit Chablis, PF obviously Pouilly-Fumée, ‘N’ stands for ‘nez’ (nose) and ‘B’ for ‘bouche’ (mouth). It would appear fairly obvious that, in the case of the C/PC, the minerality is mostly a sensation of the mouth, while with the other three groups, it is on the nose that the mineral manifests itself.
One thing I noted was that the mention of a mineral taste was almost always the last thing recorded, and, very often with an adverb like, ‘tonifiant’ (invigorating, right?) or ‘soulignant’ (that would be underlining). In a few cases, the word ‘salinity’ was mentioned.
Mark Lipton: ” I can provide a bit of help here, Nils, as one who often finds mineral notes in wine. First of all, most of the smells we associate with minerals, if not all, are due instead to small organic molecules that are associated, for one reason or another, with the inorganic substrate. One example is that ”stainless steel” reference you cite. The smell of metal is now known to be due to oxidized fatty acids that accumulate on the surface of the metal. Another example is the smell of wet stones. One chemical associated with that smell is geosmin, which is produced by plants but accumulates in the soil.”
Indeed, Professor. Yes, wet stones – often mentioned in the context of minerality in wine, and, I did a small experiment.
We have for a long time carried home stones and pieces of rock from all over the continent, to deposit them on the kitchen window sill. I picked up two, one a piece of Alpes-Maritimes limestone, and one a nicely rounded piece most likely of granite I found by the sea shore. I dunked them both in cold water and tried smelling. The round granite did not smell of anything, while the piece of lime had a definite smell – my wife compared it to sand – somehow giving the impression of dryness (despite being wet), or earthiness. I then proceeded to scrub it with a little detergent, rinsed it carefully, and, lo and behold, the smell had disappeared. Too bad I do not have the means to run some kind of spectrometry on the rinsing water to see what’s in it – geosmin comes certainly to mind. Anyway, the agent causing the smell was apparently not the stone, as such, but some easily removable coating. I suppose we could do some research on this. Anyway, this mind blowing experiment clearly indicates that a) not all wet stones smell alike and b) most likely even if they do smell, it’s not the stone but the dirt on the stone that smells.
My next planned experiment is banging two pieces of flint against each other, to find out if that produces any “gun flint” smell. Anybody done that? I mean, you read that, but, is it true?
In several of the articles I have read before sitting down to commit these thoughts to cybermedia, it has been claimed that denial of the direct absorption of mineral into the wine is the same as denial of the concept of ‘terroir’. This claim comes most often as a sort of counter, from those who reject the idea that mineral enters directly into wine – but, whoever made the claim, I would like to point out a recent discovery, also founded on solid experiments (like my experiment with the stones, only, more scientific). A recent study from New Zealand, in which a quantity of sterilized grape juice from Sauvignon Blanc, is subjected to different strains of the Saccharomyces Cervesiae yeast, collected from the grape skins in different vineyards on NZ, and, after fermentation, the resulting wine is quantified for various organoleptically active substances. It is then shown that there are measurable differences which can only be caused by the various yeast strains, as all else is equal.
My reflection is that this was in New Zealand where wine growing is fairly recent and the time for the different strains to assert themselves have been short (c 120 years, perhaps). Compare this to France and Italy where the time for local strains to establish themselves is measured in centuries – millennia, for Italy.