Prior to pursuing my degree in France, I worked in wine and fine dining. Being able to go to France and drink wine as a scientist, however, was unimaginable; I was able to see firsthand why wines tasted a certain way from one region to another based on the environmental conditions.
One of the interesting things about France is that for such a relatively small country (well, compared to the U.S.A. at least), it has a huge amount of ecological diversity that allows for a diversity of wine grapes.
Geological Structure Map of France ( Adream)
Judging by the Geological Structure map, you can see that the landscape of France changes quite a bit depending on the region. Alpine tundra, mountain forests, Mediterranean beaches--France is composed of many different landscapes that are shaped by these underlying geological structures.
Since I was living in the Loire, however, I'll focus more on how geology, climate, pedology and landscape affect the taste of the Loire wines. Explaining all of France's many wine regions might take me a lifetime.
The Loire is the longest river in France. In fact, it drains an area amounting to over 1/5th of the entire country. The Loire valley region served as the major trade route between the Atlantic and Paris, making it once the most powerful region in France after the royal kindgdom itself.
Yet, it wasn't just trade that made the Loire wealthy. The Pays-de-la-Loire is the meeting ground between four major geological structures: Massif Central, Parisien River Basin, Massif Armorican and the Loire River Basin. The Loire begins in the Massif Central, the volcanic mass of the Auvergne Mountains, and ends 630 miles (1.012 km) later in Saint Nazaire on the Atlantic coast in the Massif Armorican. Thus, the types of sediments and species are a lot different at the Loire's source than at its mouth.
Yet, it wasn't just trade that made the Loire wealthy. The Pays-de-la-Loire is the meeting ground between four major geological structures: Massif Central, Parisien River Basin, Massif Armorican and the Loire River Basin. The Loire begins in the Massif Central, the volcanic mass of the Auvergne Mountains, and ends 630 miles (1.012 km) later in Saint Nazaire on the Atlantic coast in the Massif Armorican. Thus, the types of sediments and species are a lot different at the Loire's source than at its mouth.
If you've had some French wine, you've probably heard about Champagne (as in from Champagne), Bordeaux and Bourgogne (Burgundy). If you're well-seasoned, you'll know that the Loire produces a huge diversity of wines at a much lower cost than the three more well-known regions. One reason that the Loire can produce such a multitude and diversity of wine is because the temperate, maritime climate leads to warm summers and cool, rainy winters that allow grapes to ripen.
(Check out the map in full here)
Another reason for the Loire valley's diversity of wines is the soil itself. The different geological structures make for different soil types across the region. These soil types make different varietals (types of wine grapes), and the flavor characteristics of these varietals vary distinctly between what part of the Loire they're found.
Looking at the map, you can find argillaceous (clay), sandy soil in the Chinonais, freestones in the Saumurois, shales in the Anjou, and lastly gravel and
limestone in the Touraine. These are the very soil types which are reputedly some of
the most suitable for growing vines.
(Photo from Ackerman)
I know that soils and weird French names are a lot to take in, so let me focus in a little more. I visited Ackerman Vineyards, a winery located in Saumur, France on the left bank (South) of the Loire. Most Ligerian vineyards are located on the left bank of the river because the landscape is hilly, allowing for protection from an overabundance of wind, rain, flooding and sunlight. This is in contrast to the right bank of the Loire, or the floodplains, that might be great for growing crops but is much too rich to grow stubborn wine grapes.
Because Ackerman is in Saumur, it falls closer to the sedimentary rocks of the Parisien Basin and is thus composed of rocks like limestone (whereas the Massifs have metamorphic and volcanic rock types like slate and shale).
Limestone soil is apt for growing subtly effervescent Chenin Blanc and Cabernet Franc grapes. Why? Calcareous, calcium rich soil retains water, encouraging cation exchange and thereby allowing the vines to adequately absorb nutrients. Even more, the soil itself is more acidic and helps the grapes maintain a crisp acidity.
Ackerman is renowned for making Cremant de la Loire, which is essentially sparkling wine made from regional grapes in the traditional method. The traditional method refers to a process of making sparkling wine; first, you ferment the grapes to produce a still wine. Seems simple, but then, you have a choice of 4 different methods to create the CO2 bubbles through another fermentation process. The traditional method's secondary fermentation takes places in the wine bottle, as demonstrated above.
Ackerman combines its local grapes Chenin Blanc and Cabernet Franc to make its sparkling wine. Whereas typical Champagnes taste buttery, yeasty and toasty, Cremant de la Loires will have a crisper, more citrusy taste. But, of course, this is merely a generalization. Aging, climate patterns from the vintage (year of harvest) and methods will alter the wine's profile. The difference in flavors and scents across types of wine is derived from the different grapes, soils, geology, climate and methods. It seems complicated, but, if you've had enough wine in your life, you'll be able to taste and smell the difference.
I know I've been going on for a while now, but I'm going to add one more cool fact about these wines:
The rolling limestone hills of the leftbank lead to a lot of excavations, allowing for the construction of all the famous Loire chateaux. Once the hills were excavated, however, huge caverns were left behind. These troglodyte caves were used for the secondary fermentation of sparkling wine, as the caves maintain a constant temperature of 55 degrees F (12 celsius) and balanced humidity year round, providing shelter from vibrations and light that would otherwise spoil wine.
These caves were also used to cultivate mushrooms and snails. And, oddly enough, served as homes to poorer residents of the region. Today, however, these troglodyte caves are expensive and posh homes in the countryside of a famous French wine region.
Pictured above is the town of Montsoreau and its troglodytes and tufa rock homes nestled in the hills. Or, as I'd like to think, a French Shire.
