Peter Liem's unconventional Champagne sub-region schema

In the Preface of his best-selling book Champagne: The Essential Guide to the Wines, Producers, and Terroirs of the Iconic Region, Peter Liem states that "The contemporary movement in Champagne ... is, rather simply, the acknowledgment of champagne as a wine like any other." According to Liem:

It is still not yet possible to write a comprehensive analysis of Champagne terroirs, given the lack of tools and information available compared with other historic regions. However, it is my hope that this book can in some small way help to push the dialogue further toward acknowledging champagne as a terroir-expressive wine, and to provide a foundation for envisioning that."

And push us forward is what he did with a new and unconventional schema that he has proposed for the Champagne sub-regions. In this post I examine the broad contours of this new schema and, in subsequent posts, will dig into the details of each sub-region.

The conventional approach shows Champagne's vineyards extending over 4 districts (shown in the map below) and 319 villages.  The districts are Montagne de Reims, Vallée de la Marne, Côte des Blancs, and Côte des Bar.  Montagne de Reims is a forested plateau south of Reims that is known for rich, full-bodied Champagnes and the dominance of Pinot Noir with some Chardonnay plantings in Trepail and Villers-Marmery.  Vallée de la Marne has Epernay as its core as it hugs the banks of the River Marne. This area is best known for Pinot Meunier but Pinot Noir and Chardonnay grow well here also. The soil here is comprised of a limestone topsoil overlaying layers of Belemnite and Micraster chalk.  Chardonnay is dominant in the Côte des Blancs and Pinot Noir in the Côte des Bar.  The soil in the Côte des Bar is Portlandian cap rock overlaying Kimmeridgian soil, a geologic profile that is much closer to Chablis than to the rest of Champagne.

Source: champagne.fr

The soil in Champagne is, for the most part, comprised of massive chalk deposits interspersed with rocky outcroppings and covered with a thin layer of topsoil (mix of sand, marl, clay and lignite) which requires constant renewal through fertilization.

Champagne soil (Source: Fatcork via drinks.seriouseats.com)

The slow sagging of the Paris Basin caused an upthrusting of ancient geologic formations at the outer perimeter with each formation exhibiting as a concentric, outward-facing escarpment. One such escarpment was the Kimmeridgian chain of Jurassic soils discussed previously. In the case of Champagne, the escarpment is comprised of sands, marls, and lignitic clays of the Tertiary period capping chalk from the upper Cretaceous and, below Chalons, clays and sands of the lower Cretaceous. It is the marriage of the Tertiary and upper Cretaceous strata that "is the parentage of the unique soils of Champagne."

The components of the Tertiary strata function as follows (Wilson):

• Sands -- provide coarse ingredients which help in building good soil structure
• Clays, marls, weathered chalk -- bond with particles to give good body to the soil
• Lignite -- a soft, low-grade coal which "seasons" the soil. Rapid burial resulted in concentration with iron, sulfur, and zinc from plant material.

Chalk, according to Wilson, is composed of calcareous algae (a form of seaweed) and shells of tiny organisms that settled in a uniform manner at the bottom of the Cretaceous seas. The chalk deposits in Champagne are finer-grained and more porous than other French limestone soils -- and have extremely high concentrations of the mineral marls Belemnite (younger and found higher up on the growing slopes) and Micraster (older and located on the valley floors). Chalk has excellent drainage as well as water-retention properties in that its micro-pores can absorb water during wet periods and slowly release it during drier periods. In addition, chalk will also reflect sunlight and heat thus aiding in the ripening of the grapes. The chalk soil allows the vine roots to dig freely and deeply in search of water and nutrients and also retains a constant temperature year round. Chalk weathers to a fine dust which is easily dispersed. In the case of Champagne, the Tertiary slope wash collects in the belly of the concave hills serving a binding function as well as providing mineral content. The chalk provides excellent drainage and water retention, which, when combined with the Tertiary soils, results in one of the best vine-growing soils in France.

The soils in the defined Champagne region is not monolithic, however. The Côte de Bars region of Champagne has Kimmeridgian soil of the same construct as the soils that underpin the vineyards of Chablis and Sancerre. In the Aisne region the upper Cretaceous has dipped into the Paris Basin  and the soil is comprised entirely of Tertiary clays and sands. In the area below Chalone -- referred to as wet Champagne -- the poor-permeability clays and sands of the lower Cretaceous period are dominant.

The Champagne soils distribution is illustrated graphically below.

The unconventional nature of Liem's schema is twofold: (i) He has expanded the number of subregions from four to seven. The new schema: divides the Vallée de la Marne into the Grand Vallée and the Vallée de la Marne; adds the Coteaux Sud d'Épernay; and combines the disparate zones between the heart of Champagne and Côte de Bar into a single sub-zone. The construct of this schema is illustrated in the map below.

(ii) The second area of unconventionality drives from the last point in that the soil combination of Cote de Sezanne differs markedly from the other zones with which it has been combined. In the Champagne region soils map above, the Cote de Sezanne is shown as comprised of tertiary and upper cretaceous deposits while the other partners are sited on lower cretaceous sands and clays.

In his study of these sub-zones, Liem delves into village-level characteristics. I will dig into his work in order to tease out the rationale for his proposed scheme.


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