The taste and smell of rocks

I’ve always been fascinated by rock descriptors in tasting notes. As a geologist I’ve probably licked and smelled more rocks than I should admit. But for those people who don’t spend most of their time chewing on clay and hiking across lava flows, I am wondering: how many distinct rock-like descriptors have you used or noticed in wines?

A young basalt lava flow baking in the mid-August sun does have a distinctive smell to it, but I have never noticeably smelled that in wines, volcanic soils or not. I’d describe tannins as chalky but I don’t think I’ve ever had a wine that I would describe as tasting or smelling like limestone - limestone dust at a quarry for example doesn’t smell the same as a piece of limestone you find at an outcrop somewhere, which is more likely to have a more light petrichor-like scent (as many rocks you might randomly come across do). So when I hear “crushed limestone” I’m not quite sure what people mean - any takers?

I think the term “wet rocks” is an interesting descriptor because wet rocks smell like lots of things. I was with some students out in the Hudson River Valley looking at some mélange rocks right in the river. The wet rocks in the shade were what I would consider the definition of minerality; those in the sun were too warm. So to me, “wet rocks” has for the most part been synonymous with (wet rocks in a river on a cold day). Your experience may differ, and I’d be interested to hear how.

Wet clay can be earthy, sulfurous, or vegetal, since the scent and taste come generally from what’s between the clays rather than the clays themselves. But I haven’t seen many clay-related descriptors.

Hit a quartzite hard enough with a hammer and you’ll smell smoke. Closest I’ll ever come to gunflint.

I know I’m way down in the weeds here…or deeper…but curious to hear how people think about rock characters in wine and what they mean to them.

You’re probably one of very few people who could correctly use these terms. I try to stick to broader use of “minerality”, maybe modified by stony, flinty, or chalky. For chalky, I mean the dust from what was used on old style chalk boards. That’s a very distinctive smell that I sometimes get from wines. I think a lot of the more specific or esoteric versions are mental associations that people have made, often based more on common usage (or who knows what) than the real smells of certain types of rocks. I like that you mention petrichor. That’s tied in with what I sometimes call minerality.

I rarely get more specific than minerally or stoney. But I don’t get too specific about flowers or fruits either so I’m probably not much help here.

Interesting that you mention petrichor. Despite the word having roots in the Greek for stone, it evokes earthy/smoky/vaguely organic rather than rocky/minerally associations when I read it or smell it. Apparently it derives from plant-based oils and geosmin, a byproduct of soil-based bacterial metabolism rather than rocks or minerals.

About time we got a real geologist here to help us out with that oft-used and misused term, “minerality” and everything related to it.
I’ve used different rock terms before, mostly: chalk, limestone, slate, shale, tufa, basalt, calcium. Sometimes they help define a feel more than an actual taste, almost like the rock having a living quality inherent in it.

I’ve called wines “salty.” I’ve also used the ever-nebulous “minerality.” And, for sure, I’ve said something rock-related like “wet stone.”

But… I’ve been right every time I’ve used these terms. [berserker.gif]

I’ve used wet rock, gravel and chalky. I usually notice wet rock or gravel more in the nose as opposed to the palate. Chalky to me has been more of a textural element.

I love this post. I would be interested to hear wines that you think have specific mineral type qualities that you relate to your time in the field

Wet rocks sound much better than sweaty rocks.

Good job, Kyle!

For me, I generally use mineral/rocks/clay dust, etc., to describe perceptions. We have all experienced petrichor in many forms. Wether its rain on dry asphalt, or freshly watered soil, or even dew drying in a lively forest. It is all in the mind’s eye, but the perceptions are real. As for clay, I use it in many descriptors: clay dust, dusty clay road, wet clay, clay soil. I am lucky enough to be a clay miner. I am surrounded by it every day. We dig it wet, deal with it when it gets too dry, blend it with other materials, etc. I even prospect. There is a very distinct aroma when steel auger bits heat up boring through hard clay! I have also been sand mining and processing for years. There are so many earth and soil perceptions that arise out of this as well. Maybe one day I’ll be able to use fulgurite perceptions as a descriptor in a wine I drink, probably for a Riesling.

I imagine most of the farmers here have experienced many distinct soil/rock/clay perceptions that come from their vineyards and farms.

Hear! Hear!

I dare say that nobody knows more about rocks and dirt than the real landed gentry, country squire, Mr. Carnes.

Great and interesting OP.

Wasn’t there another thread awhile back about if a particular soil imparted that characteristic into the wine? For example, if grown in soil containing limestone, does that impart a limestone taste into the wine, and if so, how/why?

Hello everyone. Minerality in wine is a relatively new area of focus. Enartis (Vinquiry) did a seminar in 2018 on this topic and there is an overview of the seminar found here: Minerality Seminar - Cellar Rats (ITB) - WineBerserkers (Note, this is a relatively technical thread)

A key point in the summary is that the relationship between the soil and minerality in wine is “fuzzy”.

It is not as simple as “grow grapes in rocks, get rock flavor in the wine”. The vines do not care about making wine, they only care about reproduction; thus, the vines to not take up flavors in their roots and put them into the grapes. The vines are interested in nutrients and those nutrients are used in a variety of ways; not just for fruit development. Part of the mystery of wine making is the incredible interactions between the raw ingredients in the fruit and the yeast to make the flavors present in wine. Not many components in grapes actually make it through fermentation unscathed by the fermentation process which is why tasting grapes rarely reflects the final wine character. Therefore, I would say that the winemaking process is much more influential (the only influence?) on minerality in the final wine than the soil/terroir of the vineyard. For example, Enartis’ research has indicated that lower Ph wines made in a reductive style (less oxygen) with a closure that does not allow for oxygen transmission will produce more minerality in the wine.

Oh I like chalkboard as a descriptor very much. To me that has both a textural (as others have noted) and a very specific dusty-type aromatic element to it.

Exactly! If you smell a rock, most of the time you are smelling microbial or plant-based products (or plant-based products that have been modified by microbes) that are present in small quantities on the surface of the rock. Most clean rocks have no discernable scent at all unless you amplify it by powdering them (at which point sniffing fine rock powder might not be a good idea)

Tufa is an interesting descriptor to me personally - because it forms so readily in closed-basin lakes (like Mono Lake in CA or the Great Salt Lake), “tufa” has a salty, almost decaying connotation to me, which I imagine isn’t shared by most people.

I really like the asphalt/soil/forest distinctions here. And the subjectivity of it all. I have a friend who does ceramics and she uses “clay” to describe a very specific set of smells that relate to her own experience - fresh clay, clay dried on her hands, clay baking in the kiln, the smell of the studio.

Thanks for the link. It would be surprising if the scents associated with rocks made it into wines in any significant way, since there are so many reactive pathways between a soil and a wine, as you indicate in your comment about yeasts. I’ve heard the same thing about reductive winemaking promoting minerality.

Muscadet to me often smells like cold water running over rocks. But some of that is cold-suppression of other aromatics.

I think it’s hard to associate specific rocky smells with specific wines because rocky smells in the field almost never occur in isolation. I spent about six weeks on a Greek island doing some detailed mapping but the primary smells I recall were of garrigue, olive trees, goats wool, seaspray. Because rocks have so little scent to them, I can only parse a lot of rock-like scents from their environments in places with few other scents, notably (1) very cold environments where plant- and soil-based aromatics are suppressed, (2) plant-free environments, such as quarries, young lava flows, samples in a lab. For that reason I think rocky smells are often invoked when there is a portion of the nose that has no discernable smell beside being very clean. I think that is part of the reason that rocky-type descriptors are used more to describe white wines than reds: there’s less phenolic competition.

Rock textures aren’t just for tannins (for which chalk and talc are the ones I’ve used most commonly). If you get playa salts wet they get a greasy consistency to them. Some white Rhones that I’ve had have reminded me of this. I think for most people this manifests as wooly-oily but my reference point is different.

I’ve spent a lot of time on volcanoes so my sulfur fault descriptors differ from some people’s, but at that point I don’t think it matters much if you describe a wine as smelling like rotten eggs or fumaroles. Neither are pleasant.

[cheers.gif]

Hi Ben. It’s interesting to get someone who actually knows about rocks to chime in. Chalk dust (for those of us who went to school when they still had slate blackboards) does bring back memories, but I’ve never found anything resembling that in wine. I never use any of those descriptions and now that you’re here, I never will!

I hope you stick around though.

this is great stuff. partially because I love finding out where other peoples interests lie and hearing them talk about things they know well, and partially because other people’s sense experiences are so specific. It also sounds like you are a very good observer of these things when you are in the field which makes it even more interesting because its so different than your everyday experiences.

Awesome stuff there. I have used “cistern” perceptions to describe a similar thoughts…