When wine has a thirst for research. © FOTOLIA, Fotolia

When wine has a thirst for research

AOC wines, a family resemblance

“Strongly coloured”, “concentrated“, “lingering in the mouth”, “heavy and rounded”, with aromas of black and red fruits: that is the style of AOC wines from Anjou-Villages-Brissac (in the Loire Valley).  This family resemblance - or typicality - is a mixture of originality, authenticity and quality that is linked to the terroir (terrain).  It is precisely this link that binds a wine to its terroir that INRA researchers have been trying to decipher for many years.  Difficult to measure, this link is nevertheless a major challenge for French viticulture, and is crucial to the production of AOC, or Appellation d’Origine Contrôlée (controlled designation of origin) wines.

Published on 11/08/2013

Soil does not make a terroir

Grapes in Alsace. © INRA, ADRIAN Michel
Grapes in Alsace © INRA, ADRIAN Michel
A survey was performed on 41 producers in the Anjou-Brissac region regarding their representations of terroir and the factors influencing the styles of their wines.  Questioned about the typicality of their wines, the winemakers were unanimous: it is the soil that binds this family together.  The influence of vineyard and winemaking practices was minor.  But astonishingly, when the same growers judged this typicality during tasting sessions, the origin of the plot did not allow them to differentiate the wines from a sensory point of view.  There was therefore a gap between typicality as it was conceived and perceived by wine producers.  In addition, the importance of harvest dates and the duration of fermentation count a great deal in the style of wines.  The researchers showed that timing of the harvest governed the composition of a wine from the biochemical point of view.  For example, the sugar levels in grapes have an impact on the typicality of an AOC wine.

Predicting the evolution of appellations

Can producers predict the evolution of appellations and the sensory typicality of wines as a function of practices?  Scientists have developed models by studying the terroir system as a whole.  An appellation area is not defined just by its soils, varieties, landscapes or sensory profiles, but is rather a particular "ecosystem" that is constantly evolving and associates soils, varieties and practices that will not produce the same wines.  Researchers have therefore preferred to analyse operational sequences, or in other words whole series of practices, rather than studying a particular practice sequentially.

And why are consumers attached to AOC wines?

What are the true expectations of consumers in terms of the gustatory quality, price or labelling of wines, or even the design of their bottles? INRA researchers in experimental economics have provided some answers to this question by analysing the motivations of purchasers relative to the different characteristics of wines.  Recent findings revealed the importance of AOC labels in the minds of European consumers and assessed their willingness to pay in different situations.  This work placed in perspective the supposed competition of "New World" wines.  Furthermore, the team showed that contrary to a common preconception, the mention of grape varieties in support of an AOC was no guarantee of a greater value being placed on wines.

Representation of a terroir and its link with typicality

Representation of a terroir and its link with typicality. © INRA, INRA
Representation of a terroir and its link with typicality © INRA, INRA
Terroir
has three dimensions: environmental, biological and human.  It endows the product with notable characteristics (an identifiable family resemblance). However, these dimensions are complex and the links between them cannot be measured precisely.  Starting from a wine and going back to the soil, the link involves winemaking practices that may partially mask the role of the soil.

Appellations

Appellations
Appellations
In France, the National Institute for Origin and Quality (Institut National de l’Origine et de la Qualité,  INAO) is responsible for appellations, labels and geographical indications. In 2010, there were 459 appellations and geographical indications relative to wine (AOC, IGP (protected geographical indication) and AOVDQS (delimited wine of superior quality, or Appellation d’Origine Vin Délimitée de Qualité Supérieure), 293 of which were classified as AOC, and in total 2889 different products (red, rosé, white, sparkling, etc., or variety names). AOP, or Protected Designation of Origin (Appellation d’Origine Protégée) refers to a product whose production, transformation and processing takes place within a determined geographical area, using acknowledged and observed know-how.  This is the EU version of the term AOC (Appellation d’Origine Contrôlée) that is used in France.  As for PGI (Protected Geographical Indication), this is a European identification that was created in 1992.  Initially attributed to specific food products with a name referring to their geographical origin, the PGI label was broadened to include wines in 2009.

e-terroir

Thanks to the efforts of INRA for more than 20 years, this on-line app is designed for winemakers and allows them to visualise thematic maps of the vineyards in the Loire Valley: different types of terrain, soil depth, water reserves, potential for earliness, etc.

http://www.carto-techniloire.com/