The Pays Nantais: Unique Geology, Enchanting Wines

May 16, 2018 | Columns

By Wayne Belding

To beat the summer heat, there’s no better source of thirst-slaking wines than France’s Loire Valley.  The wines from this extensive region are perfect warm weather wines — exhibiting an exuberant, refreshing and thoroughly enchanting style.  The valley of the Loire River stretches some 625 miles across northern France and is home to an amazing array of distinctive, and attractive red and white wines interspersed throughout a region dotted with fairytale castles, grand chateaux of the renaissance, and dwellings cut into chalky riverside cliffs.

As students of wine, we study the Loire in its entirety, with relatively short shrift given to Nantais wines.  The focus is most often on the upstream reds of Chinon and Bourgueil and the whites of Sancerre and Vouvray.  There is much to study here, of course, and wine aficionados are well versed in the various soil types of Anjou, Touraine and the Central Vineyards.  Our focus for this column is the Pays Nantais — the vineyards surrounding the coastal city of Nantes.


Geologic Map of Northern France

A look at the geologic map shows clearly that the coastal region has much different bedrock than Anjou and Touraine.  Geologically speaking, the western part of the Loire is comprised of much older rocks than the eastern reaches.  The early mountain building began here as early as two billion years ago in an event named the Caledonian Orogeny.  Those early mountains were eroded to sea level and covered with sands and muds that ultimately were buried deeply and metamorphosed into schists and quartzites. 

Then, around 300 million years ago, another mountain-building phase began.  Known as the Hercynian Orogeny, it uplifted the post-Caledonian rocks into a broad mountain range.  The Armoricain Massif, as this new range is called, provides the underpinnings for the terroir of Pays Nantais vineyards.  Subsequent to the Hercynian uplift, the shallow seas that comprised the Paris Basin transgressed westward and covered the older rocks with the chalks and limestones we associate with Anjou and Touraine vineyards. 

Because the western and eastern parts of the Loire Valley have very different geologic histories, their landscapes and soil types are different as well.  The soils formed from the old, weathered rocks of the Armoricain Massif are rich in silica and silicate minerals such as quartz, feldspar and amphibole, and this means that they develop acidic soils, which are often enriched in iron.  The upstream vineyards are on the younger limestones and chalks of the Paris Basin and the resultant soils are alkaline in nature.

The Pays Nantais is in the region known as Brittany and is the home of Muscadet, one of the most refreshing of all white wines.  Muscadet is a fresh, crisp, lively and lemony white wine.  This was not always so.  Wine has been made here since Roman times, but many of the early vineyards were planted to red grapes.  Dutch merchants began demanding lighter white wines that were suitable for distilling in the 1600’s and growers responded by beginning to plant white grapes.  Among the varieties planted was the Melon, brought to the area from Burgundy and thus named the Melon de Bourgogne. 

A brutal freeze in the winter of 1709 was severe enough to freeze the bay at Nantes and kill the vines that were growing in the area.  At that point, nearly all the vineyards were planted to white varieties and Melon became the dominant grape of the region and along the way became known as Muscadet.  Genetically, Melon/Muscadet is an offspring of Pinot x Gouais Blanc.  That makes it a sibling of Chardonnay and Gamay among others and a half-sibling of dozens more varieties.

Old Muscadet Vines in the Pays Nantais

Muscadet is a perfect match for fresh fish and shellfish. The wines are usually made by sur lie (on the lees) aging.  When yeast cells have finished fermenting a wine to dryness, they die, and the spent yeasts (known as the lees) settle to the bottom of the fermenting vessel.  Most of the world’s wines are transferred at this point to another tank or barrel for further aging. Sur lie Muscadets, though, are left on the lees until bottling occurs several months after fermentation.  Consequently, the wines are imbued with a delicate, fresh-bread-yeasty complexity to the aromas and flavors.  Muscadets can be labeled simply Muscadet, Muscadet Coteaux de la Loire, Muscadet Sèvre et Maine, or Muscadet Côtes de Grand Lieu, depending on the area of origin.

In the last decade there has been a movement among Muscadet producers to define and recognize their best vineyard sites and bottle them separately.  The first three Crus of Muscadet were elevated in 2011.  Clisson is on Granite-based soils; Gorges on gabbro-based soils, and Le Pallet on a mixture of granite, gneiss and gabbro.  These Cru Muscadets must spend longer in their lees (up to 17 months) than simple Muscadet Sur Lie.  Curiously, the Cru Muscadets cannot be labeled “Sur Lie,” even though they receive extended lees aging.  The AOP regulations for Muscadet Sur Lie require that the wines be bottled by the December following the vintage.  These first three Cru Muscadets can give us a glimpse of the future from the Pays Nantais.  They are invariably refreshing and pure, but often have considerably greater depth and nuance than most wine drinkers would associate with Muscadet wines.  They have remarkable aging potential as well, showing more complexity with 5-10 years of cellaring.  Seek some out…and situate yourself on the forefront of the new wave of Nantais wines.