Role of CO2 in the organoleptic evaluation of champagne - Experimentation and methodological contributions.
Abstract: Although visually easily detected, the impact of olfactory and gustatory CO2 in champagne were still largely unknown. Taking into account bibliography and the many variability factors, this have prompted us to start working with water, environment simpler than champagne, to compare pairs of perceived intensities of two states, with CO2 and CO2-free, before switching to champagne and characterization of perceptions. To this end, we used free sensory descriptions as available sensory techniques didn’t allowed to obtain reliable descriptions of smell due to the very rapid developments of wines by the effect of outgassing, and very significant Inter-individual perceptions differences.
We identify three main effects and their physiological origins:
the inhibition of CO2 on the aromatic molecules,
the increased acid perception
and masking of bitter perception.
As CO2 is part of a champagne, the latter with CO2, are defined as 'pleasant' and 'fresh' nose with a 'attaque_ferme' (firm attack), and 'finale_longue' (long final). The absence of CO2produces a negative hedonic perception with terms like 'evolution' (passed) nose, 'manque_dacidité' (lack of acid), 'bouche_grasse' (fat mouthfeel), 'bouche_plate' (flat mouthfeel), 'Alcohol', 'watery' and 'finale_alcooleuse' (alcoholic final).
These results also showed all the variability of the collected sensory text, its specificity, and deficiencies of sensory metrology dealing with products aromatically complex, and evolving, then we propose a new descriptive general model, the Pivot Profile©, based on pair comparisons.