Cat Pee and Rocks in wine? NO!

For various reasons when people taste wine, we often try to share our perceptions. We describe what we taste and smell through description.

We use language to communicate. The way we do this is by using descriptors, i.e. words that communicate sensorial information, the physical qualities, visual qualities, aromatic qualities and flavor qualities of the wine.

We do this in a way that can be vague or specific but generally that is shaded between positive and negative, as we usually convey both our own experience and preferences simultaneously.

We do this by use of adjectives and by analogy. An analogy is a comparison between things that are not the same, but that share a similarity. I.e. this wine tastes like blackberry, this wine tastes like cat pee, etc.

It is generally accepted and understood that when we communicate that we taste cat pee, or blackberry, or horse sweat in wine, that we are using these descriptors as descriptors by analogy only. Not because there is actual cat pee in the wine.

Similarly most people understand that when we describe mineral characteristics, i.e. the flavor or aroma of rocks or soil, that we really do not taste actual rocks and soil. Rather we are using these descriptors by analogy to express the resemblance between two things that are unlike, wine and rock, in order to communicate a similarity from a sensory perception perspective of a wine’s attributes.

In addition we can use these descriptors to communicate perceptions other than flavor and aroma in wine. For many the description of minerality is a tactile sensation rather than a flavor, i.e. the physical/mechanical impression of wine as a textural impression in the mouth. For this aspect or perception of minerality in particular, flavor scientists believe it is created by the interaction of acid and tannin on the mucosal tissue of the mouth as well as by alcohol and other compounds such as dissolved carbon dioxide.

For clarity of understanding, flavor and tactile perception are two different things. An example is bitterness and astringency. Bitterness is a flavor, whereas astringency is a tactile sensation. Yet both perceptions are related because they generally derive from phenolics compounds in wine and both are perceived synergistically with acidity. Winemakers understand that the perception of tannin that contributes a specific level of bitterness and astringency in a particular wine increases as acidity increases. (Which is why fruit ripeness, tannins and acidity are very important at harvest.)

ROCKS IN WINE? There is a very long and historic tradition that claims that the perception of mineral flavors in wines rather than analogous and similar by way of resemblance, are actually the real flavor of rocks and soil, particularly from hallowed sites with centuries old marketing traditions. These beliefs predate basic understanding of plant biology and microbiology.

Plants do not uptake rocks and soil, no more than they uptake cat pee or black berry flavors. Plants uptake ions, which are used in plant metabolism. This uptake occurs through plant membranes and is mediated by embedded proteins whose expression is controlled by genes that are more or less concentration independent. They regulate nutrient uptake, not uptake of soil, rocks or cat pee.

I have explained this to numerous wine writers whose first response is to object because of the centuries old tradition of terroir being the flavor of minerality from these hallowed sites. Basic plant biology is juxtaposed with historical beliefs, especially those related to marketing mythologies. These beliefs were not based on reality but rather on the exigency of selling wine and creating regional brands over centuries.

These beliefs die hard and slowly. Please, just try to remember that you are not drinking cat pee and rocks. But rather a complex beverage with many flavors and aromas made from fruit that was converted into wine by yeast, bacteria, human intervention and time.

Describe away, but keep it real by understanding that descriptors are used to explain and describe similarities between things that are really not the same.


Did you ever had cat pee on your sofa?

I’ve had alot more than cat pee on the sofa. [smack.gif]

Aside from flushing things from their systems, mammal urine contains many chemicals that are used to communicate: “This is my turf, bug out!” or “I’m ready to mate”. Perfume makers use some of these compounds as they add complexity and contrast to fruit, spice and flower aromas.

Of COURSE theirs no cat pee in MOST wine (I can’t vouch for a few) but it’s all good when the words are used as DESCRIPTORS.

From now on I will just say if it is good or bad. Takes all that descriptor BS away. [rolleyes.gif]

As usual, Peter, you are spot on with the chemistry of taste perception and plant biology. I always dig your posts because the force the lapsed molecular biologist in my brain to duke it out with the wine romantic. I love that fight!

Some questions though - highlighted for clarity, not obnoxiousness .

Plants (like humans) do have trace amounts of various ions. At what point are we really tasting those? I have a frame of reference of lots of backpacking and drinking mountain streams/springs. Different places would taste remarkably different, but the actual amounts of ions were almost infinitesimal. I know this as my Dad was a chemist and actually analyzed the springs of some of the places in WV. I’ve had wines which were ringers (we will defer on the psychology of taste here) of some of these water sources. I_s it so far off that think that tiny differences in trace elements can give rise to differing sensations of taste?_

Aromatic and other organic compounds are remarkably complex and end up fitting into different receptors we would not expect. At what point are organics really stimulating taste receptors in a way identical to what minerals compounds do? (Lick a rock - minerals taste and have definite taste texture.) Philosophically, if it tastes like mineral, does it matter if it isn’t literally mineral? Especially when that taste is the signature of a spot of terroir.

Thanks. Keep on being that fly in the terroir ointment!


I have seen several papers, research at Universities in France, Germany and South Africa, where they are using spectrometers for appellation of origin control by detecting trace elements in regions. Basically as a method to prevent counterfeiting of wine. The spectrometer can detect these trace elements. The human panels cannot.


How 'bout some examples? With very few exceptions, I’m not sure I’ve ever encountered anyone actually espousing this view nor can I think of any “hallowed sites” so marketed. To the contrary, the most commonly cited examples of mineral flavors in wine are universally understood not to correlate to the literal soil. Bordeaux tastes like “lead pencils,” but there’s no graphite in the dirt. Burgundy is grown on limestone and sometimes tastes minerally but I don’t think I’ve ever seen any Burgundy described as tasting like limestone.

But let’s turn to those few exceptions. Chablis actually DOES taste literally like the packed seashells in the Kimmeridgian soil there, Mosel Riesling from vineyards packed with slate actually DOES have an obvious slate flavor, Campanian reds from volcanic soil do smell and taste like volcanic rock. If you’re saying these flavors didn’t get into the wine through the roots (which is what I understand you’re saying about the science), then you must be saying either (1) that it’s a complete and total coincidence that the mineral flavors in those wines totally correlate to the stuff in the physical soil, or (2) even though they didn’t get into the wine through the roots, they must have gotten into the wine some other way. If (2) is the argument, you’re not dispelling any “centuries old marketing traditions” at all. If (1) is the argument, I don’t believe in those kinds of coincidences, and I’d bet further scientific research into the phenomenon would disclose some explanation that fits in category (2).

Hmmm. Not sure I believe that completely.

Too place in context, I routinely review medical articles for statistical crap for my wife (a physician and researcher) and also participated in a grad seminar on tasting panels which gave me an appreciation for the subtlety of them. I am not saying I don’t believe it, but do you have refs on that? I am genuinely curious.

Given the wide range of sensitivities to particular compounds, I have a weird belief that one could use community tasting notes and statistical methods to develop something more sensitive than devices.


Ahh, revisionism at its finest. I’m sorry, you can’t reinvent terroir - it’s already been invented. It’s a notion that encompasses the sun, the wind, the humidity, the fog …the PLACE - as well as the people that work the land - the land filled with rocks and cat pee. As an old soul, you should be ashamed of yourself trying to tear down a system that has served practitioners well for centuries. And to suggest that science is the answer - come on, you know full well that science is the PROBLEM. You’ve apparently gone off the deep end here. I suspect you’ve stopped the meds, hung up the cloak, and quite making the pilgrimages up to Mt. Carmel.

THe stuff I read showed how because of I presume tectonic activity or whatever reason, there was different strata as parent material to regional soils, they were able to identify trace elements in some areas and not in others. It was based on the sedimentary rock as parent material and those sedimentary rocks in different regions were different. Elements were showing up in the wine in parts per million or less, but not in other regions for example.

I do believe in terroir. It is real and is what effects the genetic expression of the vine. How it grows and ulitmately the physical morphology of the fruit that is the precusor to wine.

Terroir is vital and very complex. But its not the flavor of soil. It’s the effect of the totality of the site, soil, depth, drainage, physical characteristics, slope, aspect, thermal properties, how it absorbs retains and conducts heat, how it affects cation exchange and the availability of nutrients. All that stuff which is what a farmer has to understand and interact with in order to maximize a site’s potential. You can’t farm without recognizing it.

The terroir expresses itself differently every year, because it basically is a lense that shows differently depending on what the weather is. Terrior expresses itself differently when its hot, wet, cold, etc. Great drainage is wonderful in a wet year, great drainage is not so wonderful in a drought absent irrigation. etc.

Terroir is real and it does affect flavors, but its not the flavor of rocks.

Imagine a deep fertile soil producing vines that are rank, vigorous and vegetative. As a result the vine keeps growing and never ripens and produces fruit with green flavors. On the other hand, perhaps upslope from the same vineyard, in shallower soils with lower water holding capacity and perhaps a better exposure, the vines have less rooting depth or water availability and begin to ripen earlier in the season and have smaller canopies with more sunlight exposure on the fruit. The wine is less herbal and has riper tannin and better fruit character and it ripens every year. That is terroir.

Or it can be from cation exchange and the availability of nutrients. For example Potassium, K. It is one of the three macro nutrients, NPK, Nitrogen,Phosphorous,Potassium. It is an important nutrient, but in excess it creates vigor in vines and can induce shading. It also causes tartaric acid to salt out of wine because it is a base. It buffers the acidity and cuases high pH wines. That is terroir also!

Look at limestone sites, calcium cations have two charges, K cations only have one. Calcium limits the availability of K in the cation exchange!!!

Also look at the effect of Calcium on soil physical properties particularly in relation to clay… Calcium flocculates soil! It produces clays that instead of being water logged and that would form clay pans, as calcereous clay drains very well, and yet also has good water holding capacity.

Are you starting to understand terroir?

I get all that. But whether terroir is an analogy in tasting or reality is a less interesting question. To some extent, tasting terroir like Keith references is a socialization process where we all taste something, but agree on a vocabulary for it and use that as a standard going forward. All good.

I am more interested in at what level we actually sense differences that are there to the point where our taste and olfactory abilities - sensitive as they are - actually tell us something objective about the wine.

My favorite example is chocolate-coffee-tobacco. In a chemical sense, there is a relationship here of aromatic compounds. In the subjective sense, what a taster describes is determined by their experiences. If you are a milk chocolate kind of person, you will describe these oak-derived flavors as more coffee/tobacco. If you are a dark chocolate/87%+ cocoa kind of person, chocolate will be the frame of reference for the same compounds. Once you tease that all out, there remains the objective presence of particular aromatic compounds though. That is the really interesting aspect - leveraging the incredible sensory organs we have into something objective.


PS - My wife is an orchid freak. I am responsible for them as she travels a lot.

I totally get tiny disparate initial conditions lead to divergent results. In orchids, it is nicely binary - blooms yes/no. In wine, it is clearly analogue.


Peter, I think you just used a whole lot of words to tell us what we already know.
I don’t think anyone was suggesting that Muffy used the sauv blanc for a litter box, or that someone crushed rocks into a bottle of Grenache.

Of course it’s the use of analogy - that is the whole point of a tasting note, to convey what I perceived, while drinking the wine, to you, who may not have tasted it yet.

I’m not sure the use of the term “minerality” is meant to convey tactile sensation so much as a perception of, well, minerals in the wine. I guess I could say “wet stones” (not to be confused with Whetstone) but to me that is more of an aromatic descriptor than that of taste.

In the end, it really just does boil down to, “I liked the wine,” or, “it sucked ass.”

But where’s the fun in that?

Keith, to me rocks taste rather gritty and flavorless.

On the other hand there’s lots of things in wine, numerous compounds that have flavors and that affect the perception of the flavor of each other.

Graphite or lead to me I believe is an attribute of tannin or phenolics. In studying clones, particularly the smaller berried and more tannic clones of pinot noir, this jumped out at me.

The perception of mineral including seashell seems to be the interaction of acid and herbal elements, perhaps phenolics, in chardonnay. Not to exclude the possiblity it can also have something contributed to it by concrete fermenters.

The thing is that plants generally in the presence of the abundance of nutrients and the scarcity of others tend to horde those that are scarce and retain less of those that are abundant. Many aspects of vine nutrient status are counter intuitive. I have observed this first hand as well as studied the mechanism.

Also, I would expand on what Andrew mention from your reference, many of these perceptions are the result or subject to socialization processes. Ie. tradition, learning and peer pressure, in addition to each of us uniquely assignine values to these perceptions based on unique experiences.

I am off to cut oak or my wife is going to kill me, but will try to explain this mechanism of plant nutrient cycling later. It doesn’t work intuitively because of how vines regulate their nutrient uptake as a reflection of their environment.

I need to think a little more on some things, but want to add one element :

What I find particular confounding is that we really lack a vocabulary for the physical, tactile sensations of tasting. In some ways, I blame the dominance of the Parker school of wine notes which focuses on increasingly absurd metaphors (yet writ as fact) and fanciful taste descriptors. But to be fair, it is really, really hard to explain the physicality of so much of taste. And when I am being fair, some of the Parker metaphors like ‘sex in a bottle’ get to the root of that synesthesia of chemical tastes and physical sensations. The '01 Conseillante I had the other night was so firmly in the latter camp that words were tough to conceive which explained how that wine felt in my mouth.


So has your Avatar!

Ah T-bone the voice of reason [rofl.gif]

Ahhh…the Permanent Terroir Thread…we’ve ARRIVEN!