The Science of Minerality


Few aspects ring more passionately for lovers of WineSmith wines than their obvious minerality. The source is pretty clear -- living soil. In a recent Wines and Vines article, Tim Patterson reports that “the one thing we do know is that it has very little to do with minerals.”

In support of this silly conclusion, Tim interviews pundits Ann “Aroma Wheel” Noble and her colleague, analytical chemist Sue Ebeler of UC Davis. Both admit they are unable to make sense of the analytical data on this subject. Amazingly, Tim accepts this professed cluelessness as proof that minerals are unrelated to minerality. 

I’ve been pursuing the mysteries of minerality for ten years now, most recently with an open-minded group of CSU Fresno investigators. It’s a tricky problem. Atomic absorption data of the elemental content of organic vs conventional wines hasn’t so far yielded simple linear answers as to what minerality is. On the other hand, the sensory data is pretty clean. In other words, minerality quite obviously exists, but we don’t presently know how to measure it.

Here’s what I’m pretty sure of. There is a characteristic minerally finish to wines which is strongly associated with living soil practices (earthworms, cover crops, abandoning pesticides or herbicides). It has been described as mineral energy, mineral electricity (as it resembles electric current in the throat), and also the flavor one has in the back of the throat after eating half shell oysters or when driving home from the beach. It’s similar to saltiness, but more complex and persistent. For those who want first hand experience with minerality, I've picked out some of my own wines strong in this characteristic into a wine flight that demonstrates what I'm referring to and put a special offer on my webstore.

We don’t see this characteristic in wines from grapes grown using the methods of petroleum agriculture – bare soil, pesticide use, no earthworms present in the soil. These wines end in the mid-palate, and have a short, blank finish. They also don’t age well.

We Grapecrafters have a healthy respect for minerality for several reasons. Mosel rieslings, strong in this sensory characteristic, can age 30 years, whereas Californian and Australian rieslings die like dogs within five years. Second, when we micro-oxygenate (a process which involves continuous sensory and analytical testing for the wine’s ability to take up the oxygen without signs of overwhelm, such as a rise in dissolved oxygen, aldehyde creation or open fruit expression), wines with minerality tend to take up much more oxygen than their dead-soil counterparts. Third, minerality imparts a liveliness on the palate and a lengthy flavor persistence that sets living soil vineyards apart from other New World wines.

Pre-empting discussion is the favorite ploy of the pundits of UC Davis. These folks did not receive media training in their scientific curriculum. They’re just busy people with well-defined self-proclaimed research agendas largely unrelated to any practical needs of winemakers and unanchored in observable phenomena. In general, they display impatience with educating the public and tend to chose end runs around serious discussion of challenging issues.

Science operates through hypothesis testing. In layman’s terms, you give an idea the benefit of the doubt, play with it, and see whether it gives back anything productive. Sorry Ann -- you get precisely nowhere if you don’t play. That doesn’t disprove effects the rest of us clearly see.

The pre-emptive ploys of UC Davis “experts” manifest all over the scientific community. We haven’t really investigated the agricultural effects of phases of the moon, or biological effects of high tension electrical power lines. But lots of lazy (or financially interested) scientists use the smokescreen of “inadequate evidence” to divert attention from their own ignorance.

Tim, you’re a good journalist, but this time you got suckered by the pros. You’re not the first. But you appointed them “experts,” and all they’re really telling you is they really aren’t. Don’t buy into this nonsense. The oldest trick in the book is denying a phenomenon exists because you can’t explain it. It’s an amazing ruse -- the dumber you are, the more you get to deny.

Our trials at Fresno State are at least inquiring into the nature of this obvious phenomenon. Meantime, take heart – the sky is blue whether Ann Noble can see it or not.




Tim Patterson:

Clark, Clark, dear me. Here you are, launching into a rehearsed rant about UC Davis (what DID they do to traumatize you so there?), based on reading a highly shortened version of my December Wines & Vines Cedllar Scene column on minerality -- roughly a third of the piece. If you had bothered to read the entire piece, you would at least have been arguing against what I really had to say.

I suggest folks interested in this topic read the whole thing (I know, that's so 20th centuiry, when reacting to a web posting comes so much more naturally), and then form their opinions. I won't try to insert the whole text here, but it's instructive at least to look at the Ann Noble part of the rant. You take her and her Davis ilk to task for failing to use the scientific method -- in which "you give an idea the benefit of the doubt, play with it, and see whether it gives back anything productive." That's what she did: she tried to get tasters to agree on a definition and standard for "mineral" on the Aroma Wheel, and they failed -- that's all she is quoted as saying.

I would love it to be true that living soil makes wine taste like minerals (whatever that means), but I am srill waiting for that variation on the "minerality" story to be demonstrated. Meanwhile, I don't apreciate the suggestion that I am so easily "suckered" by the Davisites or anyone else--any more than I have been suckered by you on the numerous occasions I have consulted you for your opinions and insights.

Let's suck down a few rocks together at the Unified next month, whaddya say?



Very interesting post. The Davis people are either making absurd points like the scientists of Lagado in Gulliver's Travels or made to sound like they're making absurd points. Yes professor, up until the time when we discovered Ribena, blackcurrants were not thought to have existed. I would love to hear what the Fresno State research comes up with and have one - possibly harebrained - suggestion.

Before reading Jamie Goode's book, I believed in the “literalist” interpretation of mineral flavors in wine - probably like 99% of people - that minerals in the soil simply get absorbed into the vine and into the grapes. Just like the back label on a bottle of William Fevre Chablis would lead anyone to believe: “. . .rich in minerals and quantities of fossilized oyster shells. This provides a perfect environment for the growing of Chardonnay grapes and gives the wines of Chablis their typical mineral character.” Why not?

How about then, a hyper-literalist interpretation: that part of the bloom on grape skin is made of minerals. The minerals have simply bypassed the metabolism processes of the plant by being blown onto the skins - just like yeast - and get a free ride to the winery on the backs of the grapes! Geometrically it makes sense as a very small density on the outside of a sphere can account for fairly substantial percent of the total solids in a grape. This hyper-literalism could also account for the garrigue flavors in Languedoc wines, lavender flavors in the Southern Rhone, etc. etc. Or to quote the 70's rock sage Kansas, "everything is dust in the wind, dust in the wind." Are grapes ever intentionally washed before crushing? Didn't the Randall's Rocks experiments work up to a degree? Am I on to something here, covering well-worn tracks or just being dumb?




Clark, I don't know exactly how to say this without rankling a few feathers – so here it goes:

It's interesting that you lambaste UCD prof's for declaring that they can't nail down what causes minerality, and then essentially declare them lazy, self-serving and "closed-minded". You also imply (wrongly) that Noble & Ebeler deny that minerality exists at all…when what they are saying is that after scientific investigation that there doesn't appear to be any evidence for a correlation between mineral content of the wine and the perception of "minerality".

Nice "straw dog" you've created there, Clark.

The main problem with your argument is that after 10 years of research on your own (& with "open-minded group of CSU Fresno investigators") your results match theirs: you have found no definitive link between mineral content and minerality perception either…

Perhaps, maybe, one doesn't exist...? At least you could acknowledge that you don't have any evidence for your claim either.

Your comments regarding "living soil", and the correlation of minerality might be due to differences in viniculture, as many of the BioD proponents eschew many common techniques, and employ different (to be polite about it) viticultural practices – especially in regards to picking parameters and ripeness.

You get partial credit for your argument, but need to shore up the foundation for your conclusions…oh, and next time – show your work!

Also you might entertain the thought that "minerality" is a misnomer - just as perception of "bell peppers" is not in fact due to bell peppers being employed in winemaking, perhaps perception of "minerality" is not due to the presence of minerals...

Just a thought - albeit an obvious one...



Bruce Gutlove:


Very interesting web site here. 
It would be nice to see more discussions pertaining to the technological aspects of winemaking. Far too much mis-information is floating around out there.

Re: your comment that "the oldest trick in the book is denying a phenomenon exists because you can’t explain it"... that may well be so. But the second oldest trick in the book is almost assuredly the construction of the strawman argument.
As you do here, when you accuse Dr. Noble and UCD of denying the existence of minerality in wine. What Noble and others are saying is that there is little agreement as to a workable definition of "minerality". Without that, quantification and meaningful research are difficult if not impossible.
I would think that this is a position you'd have sympathy for, given that you've pursued "the mysteries of minerality for ten years now" and yet still "don't presently know how to measure it".

Stoking the fires of controversy by intentionally framing arguments in the most inflammatory way possible is certainly one way to get your views into print. Given that this is your own weblog, though, I'm not really sure that this is necessary.