Champagne's soil – Is it really all about chalk?
The word ‘terroir’ gets bandied around a great deal in the world of wine. A French word with no true English equivalent, it broadly encompasses all the environmental factors that give a wine its distinct character and provenance. Climatic conditions, farming practices, rootstock etc all play a part in defining ‘terroir’ but, if you talk to any vigneron about what makes their wine unique, they’ll quite quickly turn to the soil.
If you look back to the 5th Century A.D and the very origins of vine cultivation in the Champagne region, even the Romans knew to look for calcium-rich soils. Skip forward a thousand years and it was the pure chalky slopes of Aÿ that were favoured for producing the celebrated (still) white wines coveted by the French court. Even today, Champagne’s ‘Grand Cru’ villages are, with a few exceptions, the chalkiest ones.
Is chalk the only story, then? Why is chalk so important, and what happens when it isn’t there?
Layers Through Time
Understanding soil means understanding time – what came first, and what sits above it. Ninety million years ago, the Champagne region was completely underwater. Centered around Paris, a basin formed which began to sink in the middle, pushing up its edges and exposing the layers of deposits beneath. The further from the centre of the depression, the older those deposits were; Alsace and Burgundy, Metz and Dijon lie largely on Jurassic soils from between 150 and 200 millions years ago. Champagne, though, closer to the centre of the depression, sits on soils between about 40 and 150 million years of age.
It makes sense then, to start with the region’s oldest soils and move to the newest. The Côte des Bar in Champagne’s far southern reaches is almost as near Burgundy as it is the Marne river and Reims, so the soils here are much older than the chalks and clays of the North. Dating to around 150 million years ago, the Kimmeridgian limestone bedrock here is the same as that found in Chablis and Sancerre. With some of the fertility of clay, but also with useful drainage and water-holding capacity, the soils here help produce a fleshier, fruitier kind of Pinot Noir than is seen on the chalky sites of the Montagne de Reims.
As we move inwards, back north/westwards towards Paris and forwards through time, we reach a dead zone – thick, impermeable clays of the lower Cretaceous period, hardly suited to viticulture. Out of it, though, pops the outcrops of Turonian chalk of Montgueux and the Vitryat, dating to 90 to 93 millions years ago (in the Upper Cretaceous Period). This is not the same chalk as we find further North in Champagne’s Grand Crus, but these two regions nevertheless make Chardonnay their specialty; Chardonnay that loves the free-draining, water-holding capacities of chalk, which help preserve acidity and freshness in the wines.
The Golden Age of Chalk
Heading further north we start to hit the heart of Champagne – the famous chalks of the Campanian stage of the Upper Cretaceous. At around 80 million years of age, these are younger than the Turonian chalk, and form a constant presence all the way through the Côte des Blancs, the Montagne de Reims and the Grande Vallée de la Marne. But what makes this chalk so special?
There’s chalk… and there’s chalk. It’s the chalk formed of the ‘Belemnites’ – a species of microscopic, squid-like creatures – that sits near the surface in most of Champagne’s most hallowed vineyard sites. Every Grand Cru village, from Aÿ in the Marne Valley, to Le Mesnil-sur-Oger in the Côte des Blancs, to Bouzy and Verzenay in the Montagne de Reims, features large swathes of this soil, often near enough the surface for the vines to reach with their roots, which also discredits the idea that chalky substrate is best suited for Chardonnay. Vignerons in the villages of Aÿ and Mareuil-sur-Aÿ have long credited the chalk soils for the intensity and freshness that accompanies their ripe, powerful Pinot Noir.
So, what does this super-chalk do? Above all else, it is a highly-efficient sponge, draining away excess water when it rains heavily but, crucially, storing water in times of drought. One cubic metre of pure chalk can store 660 litres of water, so vines in chalk can ride out not only heavy rains, but (increasingly) dangerous droughts which can strip the crop of its elegance and acidity.
There are of course huge variations in the chalk itself. Some areas have chalk that is fractured and loose, allowing vines to penetrate but also letting water drain more quickly. Some is solid, almost impermeable, and further down the slopes towards the plains there is more ‘Micraster’ chalk (which sits beneath the Belemnite) which is not reputed to have quite the same qualities. Winemakers all over Champagne are learning how these factors can influence their wines, changing structure, acidity and aroma.
Pure chalk and almost no topsoil, though, can make for austere wines. The extremely high calcium content makes for wines with very low pH, and there just seems to be a correlation – which few can explain with anything other than an instinctive answer – between the purest chalk soils, right at the surface, and a certain tension in the wines. It needs a bit of help, which is where Champagne’s younger soils come in.
An injection of youth
The topsoil that sits above the chalk is often the topic of discussion when a Champagne producer gets out their perspex soil profiles. If it is deep and rich, such as we might find nearer the tops of the slopes (where the wooded areas are), then the vines may not really reach the chalk at all. This can change the wines a great deal; gone is some of the austerity, replaced by a little more roundness and approachability. This seems to be true in villages such as Cumières for Pinot Noir, but also in the East-facing villages of the Montagne de Reims such as Villers-Marmery, where Chardonnay in deeper topsoils produces a more rounded, generous style of Chardonnay than found in the Côte des Blancs (even with just a metre or so of difference in depth).
Erosion, too, brings down some of these Tertiary soils into the hollows in the slopes, meaning that even villages drawn almost entirely in pure Belemnite chalk can feature gentle undulations with surprisingly-deep topsoil nestled within. It’s no wonder, then, that tiny parcels can differ so much, even when just a few metres away; something we are lucky to be able to taste more and more thanks to ever-more single-parcel champagnes.
Of course, there is a balance that needs to be struck. Very cold, heavy soils can delay ripening; for instance, the vineyards right at the top of the Montagne de Reims, near the forest, are not usually the most prized for either Pinot Noir or Chardonnay. Fortunately, Champagne has a tool to deal with vineyards where chalk is not really a feature: Meunier!
Sands, Clays and Meunier
If the central part of the Montagne de Reims, the Côte des Blancs, the Vallée de la Marne and (to a lesser extent) the Sézanne is a story of the boundary between the late Cretaceous chalk and the newer ‘Tertiary’ soils, then Champagne’s more Western areas start to cross this boundary. The Marne Valley, the Ardre and Vesle, the Petite Montagne and the Massif de Saint Thierry are all regions where the chalk bedrock is simply too far down to be of much influence. Here, is it the sands, clays and marls (chalky clays) of the Paleocene and Eocene eras, between approximately 35 and 60 million years ago, that lie at the surface.
Meunier tends to be planted on these heavier soils. Why? Sometimes the marriage of soil and grape variety is more historical and practical than mystical. With the humidity of clay (and the often low-lying position of the sites), comes frost risk. Meunier, which buds a little later than Chardonnay and Pinot Noir, is a little more frost resistant. It’s this, rather than any special relationship between Meunier and these soils, that sees the grape planted widely in these regions.
Sands, such as those found on the Eastern-facing slopes of the Premier Cru villages of the Petite Montage (around Écueil and Ville-Dommange) offer better drainage, and, some believe, a more delicate and fine expression of Meunier. They also produce finer, more elegant Pinot Noir and Chardonnay than the heavier clays, which accounts for the more mixed varietal makeup in the Petite Montagne and Massif de Saint Thierry to the North.
There are, of course, many subtleties to sand and clay; the ‘green clay’ of the village of Cuisles, which holds unusual water-holding capabilities, or the rich ‘lignites’ of the Petit Morin. In the end, though, soil is just one part of the picture. There’s a whole lot more that goes into a great Champagne, and the latest generation of growers have shown that superb wines don’t start and end only with the white stuff.
LOOKING TO EXPLORE SOIL A LITTLE FURTHER?
You can pick any wine in our collection and it will tell its own story but here are a handful to get you started...
Henriet Bazin Blanc de Blancs – Chardonnay from Villers-Marmery in the Montagne de Reims. Richer and rounder in style.
Champagne Alexis Ageius – Pure Pinot Noir from Aÿ displaying the balance and finesse associated with this ancient and esteemed Grand Cru village.
Remy Lequeux Mercier G4.2 NEW IN – Excellent example of the two dark grapes from the western reaches of the Marne Valley.
Oudiette X Filles Uni Terre – Chardonnay from the 'lignite rich' Petit Moran.
Guenin Effloraison – Chardonnay/Pinot Noir blend from the Kimmeridgian soils of the Aube.