Article By: Bill Nesto, MW
The sommelier proclaimed,
I scratched my head.
Minerality is the OM of wine tasting.
But what do minerals smell like? In elementary school, I grew some minerals in science class. They didn't smell of anything.
But wine professionals frequently use the terms "mineral" and "minerality" to describe something about wine aroma and palate impact. They associate the word with wines which they believe show terroir. Most are simply communicating their impression that a wine comes from the "Old World" and is of high quality. It has been my experience teaching wine tasting that this half step towards understanding the word does not enhance blind tasting performance. I have recently pressed more credible "mineralists" to explain more precisely what they are smelling and tasting. They have responded with "wet stone", "wet dog", "chalky", "flintiness", "diesel", "cinders", "char", "high acidity", and "salinity".
There are sources of these smells which are not related to vineyard soil. Sulfur compounds in the wine can account for a good number of these attributes, particularly flintiness, wet dog and diesel. The source of this sulfur is from the use of elemental sulfur as an anti-fungal in the vineyard or from SO2 additions in the winery. During the fermentation, yeast working in either an oxygen or nitrogen deficient environment creates distinctive sulfur containing compounds that smell like a struck match, flintiness, rotten egg, rotten onion, boiled and buttered cauliflower, creamed corn, and wet dog. Sulfur-containing precursor compounds are also associated with cabernet family wines, particularly Sauvignon Blanc. The smell of chalk could be attributed to chalk coming in on the grapes. When we first dip our nose into a glass of freshly poured sparkling wine, we smell the burst of CO2 gas as chalkiness. Diesel smells are connected with Riesling varietal wines. Many people either associate this smell with mature Riesling or Riesling grown on the slate-surfaced vineyards such as are common to the Mosel-Saar-Ruwer and other areas in Germany. I find diesel in both young and old Riesling. I also find it in Rieslings that do not come from slate. Cinders and char are linked with Syrah. They are also linked with lees contact, charred barrels and dekkera brettanomyces. Acidity on the palate creates a tingling character in the mouth. High acidity in wine is more closely linked to climate, maturation and grape variety than to soil. The source of a saline taste in wine could be proximity to the sea. Salt-loaded breezes dumping their salt on grapeskins could be one source. The same breezes in the vicinity of vinification and maturation activities could also be the vector. Only the descriptor, "wet stone" defies attribution to any cause. Other than the olfactory sensation of H2O vapor, what is the smell of wet stones? If you put some stones in your mouth, what is the taste?
The Mecca for mineralists however is Chablis. The locals in Chablis intone "meeneraleetay" at every refrain. Unoaked Chablis a year or two distant from its fermentation is the vehicle for this minerality. Some locals here point to a seashell loaded clay soil called Kimmeridgean; others to a blocky limestone soil called Portlandian. Where the vrai (true) Chablis comes from seems to depend on what soil characterizes your vineyard. The Kimmeridgean and the Portlandian camps have had their shouting matches. A meeting of the minds can be found regarding the origin of each soil, seashells and marine animal skeletons. A visit to Chablis some six months ago inspired this article. When I was there everyone I spoke to intoned "meeneraleetay" but no one I met there could help me identify the attached smells and tastes in the wine.
Minerality in wine is most often associated with soils that were once upon a time immersed under saline seas or rivers. These soils contain high concentrations of marine fossils, which, in some cases remain intact and, in other cases, are smashed up into bits, even so finely as to become pulverized.
The vineyard areas with marine-origin soils were thousands and millions of years ago the bottoms and shores of basins of saline water. The marine fossils are most easily identifiable where they appear as shell beds. Such fossil shell beds are common in many parts of Italy, particularly in Central Italy. In such areas, the fossils are intact appearing as normal sea shells. I have been told that if the seal of an intact seashell is broached, the oxygen contact immediately disintegrates the animal remains. Others tell me that opening up such soils can unleash the smell of rotting shellfish, crustaceans and fish. Where there is an occasional fossil in soil, it has either been deposited by sedimentation or moved there by alluvial forces. The fossils are usually mixed either with sand, as is the case in soils around the town of San Gimignano in Italy, or with clay, as is the case in the area of Valdera near the city of Pisa.
At a February 2OO6 event in San Gimignano entitled "Chablis and Vernaccia Di San Gimignano, Affinity and Diversity", Walter Sovran, winemaker at San Gimignano's Fattoria Il Palagio explained to me how the two dominant soil types, sandy-marine-fossil and fossil-less clay of San Gimignano impact Vernaccia wine. Organoleptically, Sovran claimed that there is usually a flinty aroma and a saline aftertaste in the marine-fossil wines. He had me taste wines that came from both soils. The sandy-marine soil wines showed the pungent smell of struck flintstone. This character seemed to become more pronounced with more bottle age. A slight saltiness embedded in the wine's acidity reminded me of the taste of saltwater. The clay wines were fruitier and rounder, but were not "mineral".
Where marine fossil soils are a chalky powder, they are the result of thousands and millions of years of sedimentation. Marine animals died in the sea, floated to the bottom, where their skeletons disintegrated. Depending on the pressure of soil and water, the sediments compacted to form a calcareous chalky layer of varied friability and hardness. This kind of soil identifies the terroir of Champagne. In the Charentes area a similar kind of soil defines the Grande Champagne area where the finest Cognac base wines are produced. In Jerez in Spain, albariza is the local name for their white chalky soil.
Whether marine fossil soils are granular, blocky but friable, or fossils intermixed with sand or clay, the vine roots can plunge deeply into the soil. The more concentrated the marine fossil deposits, the less fertile the soil is. The vines are smaller, have less vegetation, and bear smaller bunches. The marine fossils, whether they are intact or in powder form, create a soil which is remarkably resistant to either an excess or a scarcity of water. According to the many growers that I have spoken to in Champagne, their vines have never shown water stress. The marine fossils can absorb the water and efficiently feed the water to the rootlets. In the Romagna hills, there is a marine fossil soil associated with the finest Albana wines. The soil is called, spungone romagnolo, meaning the "large sponge of Romagna".
Another characteristic of these soils is their high pH. Marine fossil soils are potassium deficient. Potassium deficient soils produce low pH wines. Experiments show that marine fossil soils result in high acid wines.
Marine Fossil Vineyard Areas
FRANCE Chablis, Champagne, Charentes , Chateauneuf du Pape region of France, St. Emilion (around the village of St. Emilion), and Menetou-Salon
GREECE On the western shore of the Khalkidhiki Promontory near the town of Epanomi.
ITALY Emilia-Romagna: hillsides that stretch from Bertinoro west to Imola (the spungone romagnolo); Tuscany: East of Cecina, north of Volterra, the hills of medium to low elevation in the valley of the Arno, from Siena area to Montepulciano, from Montepulciano to Radicofani, southeast of Scansano; Lazio: Orvieto; and Piedmont: Roero, Valmaggiore,
SPAIN Jerez (Albariza)
USA Paso Robles AVA in San Luis Obispo County in California, and areas south of Santa Maria in northern Santa Barbara County.
Identifying Marine Fossil Character in Wine
The outstanding organoleptic characteristics of wines that come from marine fossil soils are flintiness in the nose and a saline quality in the mid-palate and finish. Flintiness and salinity, however, are subtle characteristics in wines.
The easiest type of wine in which to find these characteristics are non-aromatic white wines that have not been fermented or matured in contact with new oak. The new oak contact masks the flintiness, particularly when the wine is young. The saline quality however can be strong even in wines which have been matured/fermented in contact with new oak. It is easiest to note wine salinity in low acid wines such as Fino and Manzanilla Sherries. The sensation of salinity occurs simultaneously with that of acidity. Though a visit to Chablis inspired this article, the several Chablis that I have tasted recently have not shown the mineral characters I associate with marine fossil soils. I need to taste a wider range of Chablis.
Flintiness in red wines is rare. Finding salinity in reds is more difficult than finding it in whites. Astringent and bitter red wine flavors confuse the perception of salinity. I sensed salinity in the San Gervasio Rosso and the two Sangioveses and the Mito from Fattoria Paradiso. Red wines that come from marine soils are light in color, usually fine and elegant, rarely big and tannic. Well made examples improve with bottle age. I heard this from a number of sources and have always found it in the wines. Merlot and Cabernet Franc have a good track record in these soils.
In bottle fermented sparkling wines, lees smell overwhelms flintiness. The two Champagnes listed at left showed salinity. In Fino and Manzanilla Sherries, flor character overwhelms flintiness but there is usually a salty taste.
Marine Fossil Wines to Try
FRANCE WHITE WINE
Domaine de Chatenoy, Menetou-Salon, 2OO5, Loire
ITALY WHITE WINE
San Quirico, I Campi Santi, Vernaccia di San Gimignano, 2OO1, Tuscany
La Lastra , Vernaccia di San Gimignano, 2OO4, Tuscany
La Lastra, Vernaccia di San Gimignano, 1998, Tuscany
Cesani, Sanice, Vernaccia di San Gimignano, 2OO3, Tuscany
San Gervasio, Chardonnay, 2OO4, Valdera, Tuscany
San Gervasio, Recinaio, 1999 (Trebbiano 8O%, San Colombano 2O%), Tuscany
Montenidoli, Fiore, Vernaccia di San Gimignano, 2OO4 Tuscany
Montenidoli, Templare, Vernaccia di San Gimignano, 2OO1, Tuscany
Montenidoli, Carato, Vernaccia di San Gimignano, 2OO2, Tuscany
Fattoria Paradiso, Pagedebit, "Vigna dello Spungone" 2OO5, Emilia-Romagna
Fattoria Paradiso, Albana secco, 2OO5, Emilia-Romagna
Fattoria Zerbina, Tergeno 2OO3 (Albana 65%, Chardonnay 35%) Emilia Romagna
GREECE WHITE WINE
Domaine Gerovassiliou, Malagousia, Epanomi, 2OO4, Greece
USA WHITE WINE
Stephan Vineyards, L'Aventure, Roussanne Estate, Paso Robles AVA, (Roussanne 85%,
Viognier15%) 2OO5, CA
FRANCE SPARKLING WHITE WINE
Champagne Ruinart, Dom Ruinart, Blanc de Blancs, 1996
Champagne Salon, 1996
SPAIN FORTIFIED WINE
Hidalgo, La Gitana, Manzanilla, Jerez
Montenidoli, Sono Montenidoli, (Canaiolo) 2OO4, Tuscany
ITALY RED WINE
Dei, Bassona, Vino Nobile di Montepulciano Riserva, 2OO1, Tuscany
San Gervasio, Rosso, (Sangiovese 7O%, Merlot 2O%, CS 1O%), 2OO4, Tuscany
I Balzini, Black Label, 2OO2, (Cabernet Sauvignon and Merlot), Barberino Val d'Elsa, Tuscany
Fattoria Paradiso, Maestri di Vigna, Sangiovese Superiore, 2OO5, Emilia-Romagna
Fattoria Paradiso, Vigna delle Lepri, Sangiovese Riserva, Emilia-Romagna
Fattoria Paradiso, Mito, (Cabernet Sauvignon, Merlot, Syrah), 2OO1, Emilia-Romagna
The author gives special thanks to the following people for their assistance: Walter Sovran (Technical Director, Fattoria Il Palagio, San Gimignano), Luca Tomassini (Proprietor, San Gervasio, Valdera, Tuscany), Thomas Rice (Professor, California Polytechnic Institute), Stephan Asseo (Proprietor, L'Aventure, Paso Robles, CA), Andrea Mazzoni (Consulting Enologist/Viticulturalist, Tuscany), Elisabetta Fagioli (Proprietor, Montenidoli, San Gimignano), Marco Antoni (Geology Expert, Tuscany), Nick Cobb (Greekwinemaker.com).