Minerality question fro Clark Smith

Clark,
Your “Postmodern winemaking” has made for excellent holiday reading.
Many of the observations in the minerality section are consistent with what we have seen in our winery. For example, many people confuse minerality with acidity. We have measured many “minerally” wines that some might describe as high acid and in fact the wines have moderate or even low-ish acidity. It is the minerality that provides that extra focus on the finish. I thought one of your more interesting theories is the idea that minerality is caused by the release of an electron (much like sensations of acidity come from a proton flow) from various metallic elements as they move to higher valences.
But I can think of many counter-examples to one of your conclusions- “It turns out that excellent minerality can be obtained on any site if living soil principles are applied.”
Living soil principles do not make a deep-soiled Borgougne blanc show as much minerality as a Chevalier Montrachet (or a better example might be a rocky high ground St. Aubin such as Chatenieres). Burgundy provides many examples of “living soil” producers that have both deep soiled and rocky soiled parcels. The rocky soils inevitably show much more minerality. So while a living soil might maximize a deep soiled site’s (still somewhat limited) potential for minerality, mineral expression seems very highly correlated with rockiness of the soil.
Is it possible that mycorrhizal fungi provide more metallic elements (in an oxidized state) to to the vine in rocky soils?

Kevin - I’m going to lock this thread, and unlock it when we have Clark on as our Special Guest

This is such an interesting area. I liken it to the discussions about lightning in Ben Franklin’s time, which were mostly confined to whether it was an inevitable consequence of God’s wrath and should not be questioned or thwarted. So we couldn’t break through that and usefully address fine distinctions until a scientific legitimacy was obtained through Franklin’s experiments.

Elaine Brown did a terrific job of setting out additional theory in the April 2013 Wine Business Monthly. Between my Chapter 8 and her text, I believe we can move beyond semantic confusion (heck, lots of words have multiple meanings) to concentrating on the one you and I are discussing, i.e. that buzz in the finish.

Barry Gump and I are forming an international working group to explore the various causal theories. We think we know that it is not caused by a simple higher level of elements, but we haven’t looked at the reductive state of those elements, and I will be on that subgroup.

Some folks think succinic acid is involved, and that’s possible, since it does have high pKa’s and so should be perceived in the finish, but I’m not aware that it has reducing properties, and anyhow, we see minerality in low TA wines. That will be another working group.

At Davis they have focused on the correlation with sulfur compounds. I think the minerality causes the reduction, not vice versa, but that’s another area to inquire into. There’s an iron crowd out there as well.

Now to your question. I have been so busy trying to sort out this level and looking for links that join together into a unified theory that I haven’t pointed my focus to the distinctions among different kinds of minerality. I love it that you and I are beyond all that and that you are beginning to peel the next layer of the onion.

I do sort of feel that limestone, schist, decomposed granite, volcanic soils and living soil impart different characteristics. I am very interested in what you and others think about this layer beneath my feet. I also think organics work much better in California to promote mychorrhizal fungi than they do at higher latitudes because our ground doesn’t freeze. We have been able to build up our populations over several years. Our experiments on the Niagara Bench were frustrating because we had to start all over every spring. One thing about rocky soils in cold climates is that they warm up fast. Slates in the Mosel have a heat capacity of 0.2, so they warm up in the Spring five times as fast as clay and are better aerated.

All that being said, our well-drraining DGs, volcanic ashes and your calcareous sections quite apparently concentrate this characteristic. Josh Jenson’s Mt. Harlan limestone is certainly minerally as hell, and very close in expression to Cotes D’Or despite no climatic similarity whatever.

I agree with you, I think Minerality causes the reduction. I also think this reductive capacity is part of why a Corton-Charlemagne or Chevalier Montrachet ages longer than a deep soiled Bourgogne Blanc.

I do sort of feel that limestone, schist, decomposed granite, volcanic soils and living soil impart different characteristics. I am very interested in what you and others think about this layer beneath my feet. I also think organics work much better in California to promote mychorrhizal fungi than they do at higher latitudes because our ground doesn’t freeze. We have been able to build up our populations over several years. Our experiments on the Niagara Bench were frustrating because we had to start all over every spring. One thing about rocky soils in cold climates is that they warm up fast. Slates in the Mosel have a heat capacity of 0.2, so they warm up in the Spring five times as fast as clay and are better aerated.

All that being said, our well-drraining DGs, volcanic ashes and your calcareous sections quite apparently concentrate this characteristic. Josh Jenson’s Mt. Harlan limestone is certainly minerally as hell, and very close in expression to Cotes D’Or despite no climatic similarity whatever.

Yes, climate seems to be very over-rated especially when it comes to “minerality”. Our warmest vineyard, Skyline, produces our most minerally wines. It is also the rockiest with only about 4 inches of topsoil. Interestingly it also has the highest CEC which might be part of equation.

I would suggest focusing on the unique attributes of vines foraging in rocky soils to help get to the bottom of this.

You would be a most welcome addition to the international working group if you’ve a mind to join us. What say?

Clark,
Sounds fun. Please let me know what it entails.

Clark,

I just re-read chapter 8 and I am still finding difficulty with this discussion.

To be clear, we don’t know what minerality is, right?

In the chapter, you say that tasting panels can identify the wines that you consider to have minerality vs the ones that you consider not to have it. Are those studies available to look at?

I’d like to suggest that several of us taste good examples of good wines made from the same grape that do and don’t, in your mind, have this minerality that we don’t know what it is or how to measure it.

Which ones of the wines you sent out is a good example of it, and what do you suggest I taste along side it to compare?

Bottom line, I am interested in getting on the same page with you regarding this sensation.

Here is an odd question: Why do we call it minerality when we don’t know what it is? Why not call it factor X?

Setting aside discussions of what it is, identifying it, and naming it…

I know that there is lots of discussion of minerality being more present in wines that are grown on rocky soils. Inherently, when there is more of something, there is less of something else. So, in rocky soils, isn’t there less ability to hold water, nutrients, including minerals? Could we be talking about something that is caused by an absence rather than a presence of something? I note in your book that you seem to think that it is not limited to certain kind of rock.