Malbec wines from Argentina: influence of climate on aromatic components and Organoleptic profile. Is it possible to stablish regional identities?

Malbec grapes have been cultivated for 150 years in Argentina. In the last 20 years Argentinian Malbec wines have emerged as a commercial boom worldwide. Today Malbec is the most planted variety in Argentina, representing 17% of 226.400 ha, and stands for 54% of bottled exported wine in volume. Producers are afraid that the growth of this wine will be limited in the future if the consumers think of Malbec as one homogeneous product. The aim of this study is to determine if there are arguments to think that we can offer to the world different Malbec wines depending on the region in which they are produced.

Fanzone found differences on Malbec no volatile compounds (Fanzone et al., 2012) according to the origin of the grapes.

During the season 2015 Malbec wines were obtained using a standard protocol from grapes cultivated at  latitudes ranging from 23° to 39° south, average seasonal temperatures from 18,1°C to 21°C (Winkler-Amerine classification III to V), and elevations over sea level from 220 to 1850 meters. Grapes were picked with 24 to 24.5°Brix and elaborated in plastic bins. Corrections of SO2 and acidity, addition of yeasts and lactic-bacteria for malolactic fermentation were also standard. After natural clarification of lees, wines were bottled. Wines were characterized by a professional tasting panel (following ISO 8586 norms), aromatic compounds were measured by GCMS (Flash profile) and tiols were extracted (SPME) and measured (GCMS). Correlations between growing season average temperature (GST), flavors (measured by the tasting panel) and volatile chemical compounds were done.

As in previews studies (Jofré, V. 2011, Goldner et al., 2008), Malbec did not present a distinctive family of flavors. By contrast aromatic profile of wines results from the interaction of many families of volatile compounds. The concentration of some of them increased with GST (norisoprenoids R2=0,947, other decreased with GST (alcohols R2=0,873), while acids, terpenes, aldehydes, C6 compounds, esters did not present clear relation with GST. Molecules like 2-Phenyl ethanol (rose) and ethyl-isovalerate (apple) increases with decreasing GST (R2=0,976 and R=0,920 respectively). GST, Winkler and Huglin explained better the variations of volatile compounds than altitude, average minimum and maximum temperatures.
In the tasting Malbec’s fruity and flower flavors taken as a whole increased with decreasing GST (R2=0,79). There was a tendency on spices and wild herbs flavors to increase with GST (R2=0,69). Some differences of flavors could be related with the concentration of some compounds.
Finally Argentinian Malbec wines presented difference on taste and volatile compounds that can be explained by temperature (GST). This will permit in the future promote a pallet of Malbec wines, creating a more interesting category of wine.