minerality of wines

7/30/2019 Minerality of wines

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Describing wines in terms ofminerality has come intovogue. While the descrip-tor is over-used and poorly

defined, with each taster experienc-ing it differently, the sensation does

exist. Even I find it impossible not touse the term when I taste white winesfrom the Loire Valley and Burgundy,Riesling from Alsace and Germany,and red wines from Priorat. A winemay be called "stony," "wet rock," or"chalky."

Grgoire Pissot (enologist at Cavede Lugny in Macon), offers a rangeof terms to describe minerality inBurgundy: chalk, f lint, salty, oil, soil,oyster shell, iodine, or smoky, likewhen you scrape rocks together. Theproblem is that these terms suggestthat the source of the taste is miner-als in the soil. Since plant scientistssay this is invalid then what are wesmelling -- or tasting? Is it somethingthe vine produces that by coincidencetastes like rocks? Unfortunately, thereis no clear scientific answer.

Popular assumptionsMineral sensation in wine is

assumed to come from minerals inthe vineyard rocks and soils, whichare taken up by the vine roots andmake their way into the finishedwine. But plant physiologists say thatthe minerals are not taken up by thevine roots.

When asked if minerals in the vine-yard and the mineral taste in thewine are connected, geologist AlexMaltman (University of Wales, U.K.)replies No, they cant be at least notin the direct way that is commonlysupposed. Maltman is not sayingminerality does not exist in wine.The term does seem a useful tasting

BY Jordan Ross

cue, he notes. It is the connotationof origin that is the problem. As soonas people say minerality, they assumethere are vineyard minerals in thewine. Sure there are tiny amounts ofdissolved ions taken up originallythrough the vine roots, but these arenot the same things as the geologicalminerals and rocks in the vineyardsoil. Vine roots cannot absorb thesecomplex geological compounds. Theyare largely tasteless anyway.

Disagreement onorigins o minerality

Anna Katharine Mansfield(Assistant Professor of Enology at theCornell Department of Food Science),

notes the almost arbitrary use of theterm. Our problem is that we firstneed to have people agree on whatminerality is. Some people use it asa third-tier term where mineralityis the term. Some use it as a class ofterms. Is it chalkiness, is it stoniness,is it wet rock? Is it an aroma, a taste(such as salt) or a tactile sensation?

I have been judging on panels withMasters of Wine, sommeliers, andenologists. When someone commentsthere is really nice minerality in thiswine we have to talk about what eachperson means by minerality beforewe can agree that it is there or notthere and whether it is nice or notnice. Right now it is a really trendyword. I am careful not to use the word

because it is so poorly defined.

What is a mineral?The term mineral can have two

meanings. Geologists talk about geo-logical minerals, while plant scien-tists refer to mineral ions, also calledmineral nutrients.

Geological minerals are chemicalcompounds; they are the mineralsin vineyard rocks and soils. Mineralions or nutrients, on the other hand,are the components of geological min-erals. Vines require 16 mineral nutri-ents to complete their annual lifecycle. For example, feldspar weathersinto its component mineral elementssodium, potassium, aluminum, cal-cium, silicon, and oxygen.

Do grapevines take up these geo-logical minerals, which in turn

W I N E a p p r E c I a t I o N

C H a l k ye a r t H yPaso Robles, California

MINERALITYRigorous or Romantic?


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2 | Winter 2012 JournalW I N E a p p r E c I a t I o N

f l i n t y g r a v e l l y s l a t e y

puts into its fruit that eventually endsup in the wine is highly controlled.There are membranes in the roots andall throughout the vine that specifi-

cally allow some things through andexclude others. Just because a planttakes something up from the soil doesnot mean it gets into the fruit.

Maltman notes that the concentra-tions of minerals (nutrients) in wineare too low to taste. Inorganic min-eral elements make up only around0.2% of a wine. In these concentrationswe simply cannot taste them, even indistilled water let alone among allthe aromatic organic compounds thatgive wines their flavor. For example,copper is typically present in concen-

trations of 1.5mg/l. Its taste thresholdin water is 3 mg/l. So for us to tastecopper, the concentration in waterwould have to be 2,000 times greaterand massively more in wine.

Whatare we tastingor smelling or eeling?

Tasters often define mineralityas the smell of wet rocks followinga summer rain. But rocks do nothave an odor, so what are we smell-ing? According to a paper written byAustralians J. Bear and R. G. Thomasin 1964, after a rain what is assumedto be the smell of rocks is petrichor ---the scent of organic compounds thatwere released from plants and fell onthe rocks and soil during dry periods.

Mansfield explains, The authorssuggested that when it rains, vola-tiles contained in the dried plantmaterial are released, so what youare smelling is not the rock itself buta compendium of all the plant lifearound those rocks which is kind ofan interesting argument for terroir.You are only smelling organic matterthat has settled on the rock; if you geta really clean rock it does not havea smell. The authors called this rockaroma or rock essence petrichor, andit would vary based on the kind ofplants around the rocks.

Gavin Sacks (Assistant Professorof Enology at Cornell) makes animportant clarification: A rock anda mineral are not the same thing. Amineral is an ordered solid with awell-defined chemical structure. A

Knights Valley, California Applegate Valley, Oregon

impart a mineral character to thewine? Scientists say they do not.The vine is unable to take up theseminerals, explains Carole Meredith(Professor Emerita in the Departmentof Viticulture & Enology, Universityof California, Davis). A mineral isa complex chemical compound andwhen it gets in the area near the plantroots it is broken down into its com-ponent ions. Grapevines never takeup a mineral, only the components ofminerals.

Although the component ions canbe taken up by the roots as they areneeded by the growing vine, only acertain proportion of mineral ionsend up in the grape. A portion ofthose that do end up in the must areused by the yeast during fermenta-tion. Potassium is lost as potassium

bi-tartrate crystal s during ageing.Meredith adds that the plant is not

just a passive fi lter. What the plant

rock is composed of one or more min-erals, but may also include organicmatter think about oil shale, as anextreme. Usually we encounter rocksin nature, not minerals. Rocks couldcertainly have a smell; it is just not themineral part we are smelling.

Where do you fnd it?Christophe Rolland (ex-somme-

lier at the Bellagio in Las Vegas,Alain Ducasse in Monte Carlo, andLAuberge de lIIl in Alsace) findsminerality in wines from the mostnorthern vineyards where you havea single grape variety. In regionssuch as Alsace and Burgundy, thesoil has a tremendous impact on winecharacter. In Champagne, especiallywith Chardonnay, you also have tre-mendous mineral quality. The car-

bonation I think brings this qualityout. But you have to work with a smallgrower who works in a particular


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area or with a ngociant who workswith a specific area. Champagne isharvested at low maturity and highacidity, which works in favor of min-

erality.

Link to acidityRolland mentions the one point

where there is agreement -- the rela-tionship between acidity and min-erality. High acidity is one of thenecessary conditions for the expres-sion of minerality. I think the acidityreinforces the minerality. High acidvintage like 1996 or 2002 in Burgundyprovide more support for the miner-als. Minerality can be fragile. Whenyou do lees stirring, you try to enrich

the wine, but you lose some of thevivid, crisp, pungent character thatprovides that edge, which is more inphase with the minerality of the wineand less with the buttery, rich, waxy,honey character.

Pissot concurs, adding that the termmineral is, at times, used whenacid would be more appropriate.In my opinion, the mineral flavor isindeed linked to the level of acidity.All the vineyards mentioned are innorthern Europe, with colder cl imate,therefore with sometimes under-ripevintages. This is why the mineralquality is sometimes misused by peo-ple, describing a wine as mineralinstead of under-ripe, or acid, inorder to improve the description ofthe wine.

Mansfield says that the relationshipbetween acidity and mineral flavor isa good hypothesis, but just a theoryat this point; some suggest that it isa combination of a lack of fruitinessand high acidity.

Rainer Lingenfelder (GermanysPfalz region) says, It certainly hasnothing to do with what one can mea-sure as potassium, calcium, magne-sium, boron, or whatever in the wine.It probably has more to do with acid-ity and actually a certain un-ripe-ness. People find minerality in ourwines, more in the ones with higheracidity. I myself use the term veryrarely, as it is much less apparent inour conditions (and soils: sand, loess,and chalk ?? is there some connec-tion to the soil after all?? Well, I guess

our sites just produce ripe fruit on aregular basis.

The grape variety also makes a dif-ference. It is true that Riesling shows

more minerality than Scheurebe evenwhen they grow side by side. Rieslinghas more acidity than Scheurebe -this is probably the reason. I findmore minerality in Saar wines thanin Rheinhessen or in Pfalz where Iam from.

Nik Weis (who runs the Moselestate of St. Urbans-Hof) concurs.Especially when acidity is part ofthe game, minerality comes out more.My Ockfener Bockstein located inthe Saar is a higher acidity wineand shows more minerality than

my Piesporter Goldtrpfchen. TheOckfener Bockstein is embeddedin a mountain range. At night thecool air flows from the mountaindown into the valley. The PiesporterGoldtrpfchen does not have thatkind of a chilling effect; it is alwaysfairly warm.

In addition to these climatic tem-perature differences, the two vine-yards have different soil composi-tion, which affects the amount ofheat the vines receive. The soil in thePiesporter Goldtrpfchen is a highlydecomposed dark blue Devon slate,which makes it heat up easily. Thesoft and waxy structure retains thewarmth long into the evening. In theOckfener Bockstein you find a greyslate soil with very hard and solidrocks, which also have some quartzenclosures. The acidity is more pre-served here than in Piesport.

Mineral expression appears to comeless from the soils mineral composi-tion and more from the climate andhow the soils physical characteristicsinf luence ripeness and therefore acid-ity.

Meredith agrees with the aciditythesis, Minerality is probably relatedto the perception of tartness. Lean,tart wines have this. Why people callthat mineral i s probably just conven-tion and may not have anything todo with real minerals at all because Ido not think people have a clear ideawhat minerals taste l ike.

Mineral character is most fre-quently cited in wines grown in

limestone-rich soils; as if the chalkysensation one finds in Chablis orRiesling in Alsace is derived directlyfrom the soil. In reality, limestone

soils are alkaline and produce wineswith higher acidity, explains MarcDubernet (who has a doctorate inenology and has managed LaboratoireDubernet in Narbonne, France for 40years). The favorable terroirs for theappearance of minerality are thosethat bring together a cool climatewith a good late growing season andalkaline soil types (chalk, limestone,etc.). It is well-known that, for anygiven climate, alkaline soils lead tohigh acidity and low pH in wine,while acidic soils lead to must with

lower acidity and higher pH.Dubernet adds that while the acid-

ity level is important, the balance oforganic acids in wine is fundamental.It is clear that malic acid plays animportant role. Its taste is decidedlymore mineral than that of tartaricacid. A higher amount of malic acidat harvest time will always be a favor-able factor for minerality.

Is minerality a taste?Weis describes minerality as less

of an aromatic and more of a tastequality. Minerality is not somethingthat you smell. It is much more a saltyimpression that has an effect on theway the acidity comes along or thesweetness. I describe minerality interms of saltiness, when a wine hasa salty finish just like some mineralwaters do. The salty characteristic isalways derived from minerals in thesoil.

For example, when you talkabout chalky minerality that would

be something you would find in aChablis or a white wine from theCote d'Or, whereas in the Mosel wehave a kind of ashy minerality whichdefinitely comes from the slate soil. Ithink that the minerality in the Saar,where I am from, comes through in adifferent way, maybe even stronger,and the reason for that is the mostlyhard gray slate soil with quartz andsome iron veins. In some parts of theSaar there is so much iron that theslate has a reddish color, a rusty red.



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Is minerality amoutheel sensation?

Weis adds, Even more so it influ-ences the mouthfeel of a wine. The

minerals in Mosel Riesling allowus to leave more sugar in the wineto balance out the acidity and it stillfinishes dry. The sweetness is offset

by the saltiness the margar ita effect .The salt around the rim of the glassis important; the acidity of the lemonor lime and sweetness alone wouldmake it taste just sweet and sour. Thesalt creates a feel of effervescence, afeel of refreshing spritz.

Determining whether mineralityis a taste, smell, or mouthfeel sen-sation may prove to be more dif-

ficult than one would think. Dr.Larry Marks (Fellow of the John B.Pierce Laboratory and Professor ofEpidemiology and Psychology at YaleUniversity) explains, When you takesomething into your mouth you tryto figure out what part of it might besmell; that is very hard to do, evenwith practice.

If you take something fairly sim-ple, vanillin, the essence of vanilla,at low concentrations, even though itdoes not stimulate taste receptors atall, people will put it in their mouthand say, Gee -- it tastes a little sweet,even though there is no activation ofsweet receptors. You put in a littlesugar and they say, That is a reallygood sweet vanilla taste. They cannotdetermine which part of it is taste.

The flavor of anything takenthrough the mouth has an enormousnumber of components. It is a com-plicated and poorly understood inter-action among gustatory response(taste), olfactory response (smell),and somatosensory response (touch,mouthfeel). You want to tease theseapart but you cannot do it just byreflecting on your experience. If wecould do that we would never havehad to build laboratories, and evenwith laboratories it is hard to figureout.

Where does minerality come from?Do chalk, flint, or slate soils impart

chalky, earthy, flinty, gravelly, orslatey characters to a wine? Meredith

believes the origin of minerality ismore complicated. It is something

that the plant is doing in responseto its total environment, which willinclude the soil, but also the air andthe temperature and the wind and

how it is farmed. The plant ends upproducing the things that you taste; itis not just transferring them from thesoil into the wine. You have to givethe plant more credit; it is not just apassive conduit for the things in thesoil.

Weis believes mineral flavors comefrom constituents in the soil, I dothink that minerality comes from thesoil. These minerals influence themetabolism of the yeasts and there-fore the fermentation flavors in awine.

Maltman suspects that althoughthe concentrations of inorganic ionsderived from the vineyard soils aretiny, they might influence organicchemical reactions involved in vinegrowth and during vinification. Itcould be some combination of theresulting organic compounds ratherthan the ions themselves that givewhat people call a minerality taste,he suggests. In other words, therecould be a connection between thevineyard geology and minerality, butin a way that is very indirect andcomplex - and at present unknown.

There is an absence of hard datashowing that what we call miner-ality correlates to certain levels ofspecific minerals or ratios betweenminerals, or perhaps even in specificredox couples, says Randall Grahm(Bonny Doon Vineyard, Santa Cruz,CA). Probably the disulfide/thiolcouple is the one that is most interest-ing, as that is the one that is in oursensory wheelhouse. Here Grahm istouching on an interesting idea: thatreduction can show itself in a formthat leads to the use of the miner-alic descriptor by tasters. Overall,he thinks that minerality in wine hasmany sources, and that it correlateswith this list of phenomena:

1) Mineral-rich soil, that is, highlevels of exchangeable cations,

2) Healthy soil microf lora,3) Low yields, that is, a favorable

ratio of rooting mass to fruit volume,4) Old vines,5) Non-irrigated soil, especially soil

that is not drip-irrigated,6) Maybe smaller trunk diameter

and head-trained (gobelet) vines (bushvines),

7) Later-harvested vines (all thingsbeing equal), but not over-r ipe grapes,

8) Ability of wine to tolerate oxida-tive challenge after bottle being openfor several days,

9) Ability of wine to age andimprove in the bottle,

10) Mineralizing processes in soil- the presence of particular animals(sheep), manure, compost.

It is certainly possible to confuteminerality with other phenomena,adds Grahm, such as the presenceof Brettanomyces (that is more iodine

and sweat), greenness (that is likelygreen seeds or perhaps inclusion ofstems), tannin (that is more of a senseof astringency), and various volatilesulfur compounds such as thiols anddisulfides. In relation to the lastpoint, he adds a question: Do miner-als in wine tend to make a wine more

backward or reduced, or is a ten-dency toward the formation of thiols

just another word for minerality?

ConclusionThe lexicon of wine is full of

abstract terms that are hard to define.What is a layer of flavor? Whatexactly is a wines mid-palate? It isok for scientific fact and romance tocomingle? But minerality is importantand different. As a major componentof some of the world's greatest whitewines; it has become a code word forhigh qual ity.

Its popularity could be a backlashagainst the big, oaky, buttery style. Aswine drinkers become more sophisti-cated, they are attracted to wines thatreflect a place rather than the hand ofthe winemaker. Minerality is one wayto associate a wine with the vineyardor region in which the grapes aregrown.

Since how a wine tastes is a com-bination of so many factors, someof which are impossible to measure,we look for something tangible, likerocks, to explain what makes a winedistinct. It is easy to oversimplify anddraw the wrong conclusion. Rocks,rather than directly imparting flavor,



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Winter 2012 | 5Journal

play a more important role in a soilsphysical structure, which affects howwater is made available to the vine.

Minerality is an actual sensation,

but whether it has anything to dowith minerals in the real world isdoubtful. It is a bit of an abstraction- part romance, part reality, a movingtarget, different from region to regionand even within a region.

Arnaud Saget (who producesDomaine de la Perrire Sancerre andwines from nearly all Loire Valleyappellations) feels that Pouilly,Sancerre, and Savennires are thethree dry appellations that show the

best expression of minerality; but notthe same minerality. Saget explains,

Each appellation expresses mineral-ity in different ways. While Pouillygives more impression of crunchingon a rock, Sancerre shows more ele-gance and more purity. Savenniressometimes shows an expressionof minerality very close to some

Rieslings from Alsace, with petro-leum aromas.

Minerality probably does notdescribe a specific sensation but a

class or category of sensations foundin wines with high acidity and lowfruit expression; although the fruit-scented German Rieslings are anexception to that rule. Because it has

become associated with high quality,we tend to look for it.

Since so much of perception isbased on expectations, we tend tofind minerality where we think itshould be. The next time you open anaustere white wine with high acidity,choose your words carefully. n

Jordan Ross is a graduate of the Departmentof Enology & Viticulture, University ofCalifornia, Davis. To view his previousarticles go to www.Enologyinternational.com. Ross works for Pasternak Wine Importsin Harrison, NY.


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