The World's Top 10 Wine Soils
By Sunny Brown
It's no secret that those in the know in the wine biz get all giddy when talking about soil. Wine lovers and makers alike droll on and on about how one vineyard has subterraneous tufa while another vineyard boasts a blend of calcareous marl and limestone clay. While it may take a degree in Geology for all of these terms to make sense, it is easy to see that certain places in the world are perfect for growing grapes.
Which brings us to the question of Why? Lots of places have warm weather and low amounts of rainfall. There are plenty of fine winemakers who are not limited to the more famous regions. So what is it about Burgundy, and the Mosel Valley, and the Rutherford Bench that set them apart from so many other quality areas?
It isn't because they were there first, or because of dumb luck that certain regions have become famous, which brings us back to just one very important thing- the soil. Winemakers for centuries have plotted out through hard work and lots of trial and error specific sites that not only have unique geological compositions, but that also grow the finest grapes in the world for wine.
What follows is our Top Ten list of great winegrowing soils. The criteria are thus: Unique qualities, historical importance and market appeal of the wines. As with any list, this is bound to offend those who are omitted or feel slighted at their ranking. Don't like it? Feel free to add your comments to the bottom of this article.
A quick primer on soil types
Alluvial - A combination of clay, silt, sand and gravel that forms over time from mineral deposits left by running water.
Calcareous - A soil primarily composed of calcium carbonate and high in chalk or limestone as well as fossilized shells.
Granite - A hard and granular rock with a high content of crystals, particularly quartz.
Jory - A volcanic soil composed mostly of basalt, which is in turn a hard and dense soil that often has a glassy appearance.
Limestone or Chalk - A soft soil made primarily from fossilized seashells.
Loam - A crumbly mixture of clay, sand and silt.
Marl - A crumbly mixture of different clays as well as calcium and magnesium carbonates with fossilized shells mixed in as well.
Sandstone - A combination of silica and sand compacted together by pressure and time.
Schist - A metamorphic rock derived mostly from clay, but it can be made from several other rocks. Schist is a soft rock that flakes and breaks easily.
Shale - Layers of clay-like, fine-grained sedimentary rock. On the surface where the shale breaks it often forms beds of sharp fragments.
Tufa - A mix of silica, calcium carbonate and sometimes volcanic ash that has been deposited over time by streams, lakes and other water sources.
10 – Mendoza, Argentina
While the combination of sand, granite, schist and alluvial deposits are hardly unique to Argentina, these soils in conjunction with the ridiculously high altitudes at which the grapes are grown have created a unique growing environment. Grape growing begins at 2,500 ft. up in the foothills of the Andes, a height well above all but a scant few European vines, and continues in many places to over a mile up or more.
Lots of sunshine during the day, very cool temperatures at night and lots of dry mountain air combine to provide a very long growing season for the spicy Malbecs, rich Cabernets and full-bodied Bonardas of Mendoza. The wines of Argentina are said to boast very high concentrations of reservatrol and antioxidants due to the long hang time on the vine. All that flavor and health benefits, too? I'm hooked.
9 – Coonawarra, Australia
The visually arresting Terra Rossa, or red earth soil of Coonawarra also occurs in a few places around the Mediterranean, but this swath of earth some 10 miles long and less than a mile wide is quite the oddity in Australia. The soil, which is literally red, is formed by a unique combination of events: This area was once a seacoast, and the limestone soil lies over top of a sandstone base. The limestone has dried over the course of many millennia, and the breakdown of the soil as it starts to erode has caused iron deposits within the soil to oxidize, thus imparting the deep orange and red hues.
The resulting soil is rich in nutrients and minerals, drains very well, and provides a thin layer over the limestone beneath. Many wineries have found this to be a perfect growing environment for Cabernet Sauvignon, with Bowen, Parker Estate, Wynns and Highbank Vineyards among some of the best.
8 – Priorat, Spain
Around the foothills of Montsant (the Holy Mountain) resides an almost otherworldly soil type that cannot be duplicated anywhere else on earth: Llicorella. This mix of dark slate and quartzite that developed in Paleolithic times is dark in color but glitters in the sun from the high crystal content. It is rocky, porous and free-draining which forces the roots to dig way down deep (up to 25 meters) into the bedrock to find pockets of water and nutrients.
One of my favorite stories in the wine world is that of the cost of the local donkey in Priorat. Almost abandoned as a wine region in the 1970s because the hills are so steep and must be worked entirely by hand, innovative winemakers from across the world have settled in this area today to take advantage of the unique combination of soil, climate and old vines of Syrah, Grenache and Carignan. Though lots of new investment has flooded into the region, the vines must still be worked by hand so the price of the local burro has gone up ten fold!
7 – Tuscany, Italy
Soil purists will tag me here since Tuscany is actually comprised of several different soil types that range from tufa and volcanic soil to sandstone and limestone clay. But it is in this diversity that the beauty of Tuscany lies: There are so many different sub-soils that there is a perfect home for each individual grape variety, no matter what type of soil it prefers.
The higher altitudes of vineyards around San Gimignano make a great home for Vernaccia. The rocky, low-vigor soils of Chainti and Montalcino are perfect for Sangiovese, while areas in between boast more sand, clay and alluvial deposits, a great spot for international varieties that make up the backbone of the great Super Tuscans.
6 – Châteauneuf-du-Pâpe, France
The best vineyards in the new home of the Pope are covered with galets, or pudding stones as they are often called, which are smooth, oval-shaped stones that were formed from the many centuries of floodwaters that poured through the Rhône Valley after the last Ice Age. The galets collect and retain the heat of the sun, which they then radiate back onto the vines during the cool of the evening.
The results are wines that are spicy, rich, full-bodied and higher in alcohol than many of their brethren elsewhere in France. For those that like Syrah and Grenache, if you haven't tried a good 'Neuf-du-pâpe, then you haven't yet begun to live. As a side note, it is a good thing that the vines take so readily to this soil, since some of these vineyards are so rocky that they look like the bottom of an aquarium. What else on earth could grow there I have no idea.
5 – Alsace, France
There are many who would argue that Alsace should be #1, but I think the argument could be made for almost any of the top five, a testament to just how famous these places are. Flat out, it is soil that makes the wines in Alsace. Yes, they have a break from the weather provided by the rain shadow of the Vosges Mountains, but the real beauty of this 70 mile strip of grape deliciousness lies in the mix of 20 different major soil compositions that line these east-facing foothills.
The Grand Crus of Alsace read like a laundry list of famous soils: The sandstone of Kitterlé, the limestone of Zinnkoepflé, the granite of Brand, the warm volcanic soils of Rangen. The list goes on and on. Each vineyard over the years has developed a reputation for which grapes grow best within its hallowed grounds. The Grand Cru of Schlossberg, or Castle Hill as it is translated from German, is free-draining, stony, and rich in granite. Subsequently Riesling is a natural choice here. While just a couple hundred yards away the Grand Cru of Furstentum has a higher proportion of limestone clay and is famous for juicy and rich Gewürztraminer.
Many of the famous vineyards in Alsace can trace their wine-growing heritage back to the 1300s. Despite wars, changes in nationality, changes in climate, and even phylloxera, this strip of vineyards barely a mile wide continues to crank out world class white wines.
4 – Rutherford, Napa Valley
Perhaps André Tchelistcheff said it best: "It takes Rutherford Dust to grow great Cabernet." While the man many consider to be the founding father of great American wine was not referring to one particular soil type, there is no disputing the importance of Rutherford in American winemaking or in the world of wine as a whole.
So what is Rutherford Dust? Well, I can tell you what it is not- It is neither an actual soil type nor an additive to the wine. It is a dusty and spicy berry element that can be found in all great Rutherford Cabernets. Some have described it as mocha, others as Allspice, but regardless of specific flavor descriptors it is an ever present ethereal nuance that sets the wines of Rutherford apart from its prestigious neighbors of Oakville and Saint Helena.
This is not to say that Rutherford is without merit in terms of soil. There are three distinct alluvial fans that were formed from the runoff of mineral deposits left in the valley floor over eons of time. They range from gravelly to sandy to loamy, and some of the most famous vineyards in the United States sit atop the shattered sandstone and limestone base. Bosche, Martha's Vineyard, Bella Oaks, the Opus One vineyards- more than enough to keep any collector happy until the end of time.
3 – Bordeaux, France
Without even mentioning the clay soils that dominate the Right Bank, Bordeaux still boasts some of the most hallowed hills on earth in terms of wine. The croupes, or mounds of gravel that spread out like ripples on a pond in the Haut-Medóc have for centuries provided wine lovers with many a muse to pour their love and admiration into. Up until the 17th century most of the area was swampy marshland until Dutch engineers drained the waters revealing a rocky gravel soil rich in minerals and perfect for growing grapes.
Since then the best examples of Bordeaux have been considered only the greatest and most expensive wines in the world. The first growths command such respect that the wines are sold from the winery long before they are ever even bottled. Five million cases of wine per year are produced in the Haut-Medóc alone, a staggering number for an area known for such high quality.
Further to the south fine white wines are produced along with reds in the arid sandy and gravelly soil of Graves. Bordeaux also has the distinction of being the only region on earth famous for all three of the major styles of wine- white, red and sweet. Sauternes and Barsac produce some of the greatest, most unctuous and rich and decadently sublime dessert wines on the planet.
2 – Mosel, Germany
While there are certainly other famous spots in Germany for Riesling, no spot holds as many famous vineyards in such a short stretch of river as that of the steep slate slopes that line the Mosel River along the western edge of the country. The steep walls of the valley protect the vines from harsh weather and the steep angle provides a more direct exposition to the sun as well as sunlight that reflects off of the river back onto the vines. The slate warms quickly in the sun and retains the heat of the day late into the cool of the evening.
These factors combine to provide a long, slow ripening period for the fickle Riesling. There is no grape on earth that is more of a reflection of the soil that it is grown in than Riesling. It seems to absorb every nuance of nutrient and structure of the soil and in the best examples parlay them into the glass with such clarity and focus as to seemingly scream to the taster of the soil from whence it came. Rieslings separated by just one lonely little bend in the Mosel River will taste entirely different, no matter the similarities in production methods or even ripeness levels.
Of the great vineyards, the Sonnenuhr boasts deep, blue-gray slate, while the Erdener Prälat has dark red. The red volcanic soils of the Urzinger Würzgarten (Spice garden) create wines that are just as they sound- spicy and with depth of character. The list goes on and on. I urge you to try each different vineyard. While the subtleties of each individual soil type may not be apparent at first, they will stand out over time. And if not you are still drinking some of the greatest white wine on earth.
1 – Burgundy, Champagne and the Loire Valley, France
A basin of limestone marl that starts in England runs all the way down through the vineyards of Champagne, the Loire Valley and ultimately Burgundy. It is on this ridge, known as the Kimmeridgian, that the best vineyards lie. The soil varies from hill to hill, but all contain at least some of this limestone clay which is heavy with nutrients from the fossils of shellfish from eons ago.
The success of the vineyards perched atop this chalky soil has been widely known for centuries. Champagne was famous long before a certain monk put a few bubbles in the bottle by accident. The Grand Crus of Burgundy are separated by walls that date back to monastic times and names that hail from ages gone by. The Grand Cru of Corton-Charlemagne was said to be the said to be the king's favorite vineyard some 1,200 years ago. The best vineyards of the Loire mix limestone, clay and silica to form a flint and sand mixture known as silex.
For just as long as they have been famous, attempts have been made to duplicate their successes. It was long thought that quality Pinot Noir could not be produced outside of Burgundy. Tasty sparkling wine is now made in many other parts of the world, but it is not Champagne. The best wines of the Loire Valley still hold a haunting mix of earth, fruit, structure and nuance that is impossible to duplicate elsewhere.
It is in this spirit that I feel that the Kimmeridgian soil is the most famous and important on earth when it comes to fine wine. The quality, longevity and unique features of this particular blend of limestone and clay have driven the wine world for centuries. Battles have been won and lost, fortunes come and gone, and even nations have been created and remade in the time these wines have been famous. And for that, there is no comparison.