A chemical analysis of Malbec wines from Argentina has shown that the 鈥渢erroir鈥� of a vineyard can be detected in different vintages. Such analyses could help reduce the massive problem of wine fraud, in which one drink is passed off as a superior version or adulterated with cheaper products.
There has long been an idea that terroir 鈥� the combination of local geography, geology, climate and wine-making practices 鈥� gives a unique flavour to a wine from a particular place. This is why wine-growing estates, such as Chateau Lafite or Chateau Margaux in France, claim that no one else can make a wine like theirs. But evidence tying the confusion of causes of terroir to a consistent, measurable effect in wine has been hard to come by.
Now, in Argentina, Ariel Fontana at the National Scientific and Technical Research Council and his colleagues, working with Roy Urvieta at the Catena Institute of Wine in Argentina, have compared Malbec wines from 2016, 2017 and 2018, each produced under standardised conditions in different 鈥減arcelas鈥� of vineyard in Mendoza province, which is famous for producing this red wine. The team says 11 of 23 parcelas could be identified by chemical analysis with 100 per cent certainty, and the other 12 could be identified with up to 83 per cent certainty. The vintage could also be pinpointed.
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The team used liquid chromatography to quantify the presence of 27 compounds in the wine, including anthocyanins, phenolic acids, flavanols and flavonols. Compounds like these contribute to factors such as the feel of the wine in the mouth and colour. The varying concentrations of each compound could be consistently linked to certain parcelas. Some phenolic compounds were at higher concentration in areas where ambient temperatures are lower, for example.
Most of these compounds originate in the grapes that are made into wine and their proportions can vary with grape variety, soil characteristics and the climate. Other compounds are created by chemical reactions during fermentation and ageing.
鈥淭erroir remains one of the most intriguing challenges in today鈥檚 wine world, largely because what terroir encompasses is not universally understood or accepted,鈥� says Fontana. 鈥淭his study will be the starting point to understand and better define the terroir, not only for Malbec and Argentinean wines, but also for other varieties and regions over the world.鈥�
The results echo those of a in the C么te de Nuits region of Burgundy, France, in 2014, which revealed differences in the compounds in wine from two different vineyards, but the year had a bigger effect than the vineyard.
鈥淎ttempting to deconstruct which factors are involved in terroir and their relative importance is formidably difficult,鈥� says Alex Maltman at Aberystwyth University, UK. 鈥淲hile I鈥檓 a bit surprised they鈥檝e managed to find those correlations despite all the vagaries of natural vineyards and the wine-making, I have no problem with the work.鈥�
Being able to definitively link wines to a specific place could have its advantages. 鈥淕iven the very limited success of chemical analysis in terms of predicting consumers鈥� flavour experience, this represents a nice use for the chemical analysis data,鈥� says Charles Spence at the University of Oxford. 鈥淔ingers crossed it can put a stop to the various wine scandals where one wine is sold as another.鈥�
Scientific Reports
