Chemical changes


After extraction, the eau-de-vie “digests” the wood

After extraction, the eau-de-vie “digests” the wood.

This is also referred to as the “marriage” of the eau-de-vie and the compounds in the wood

With time, the taste mellows, the bouquet becomes richer and the colour deepens

Le vieillissement du CognacAs the years progress, the smell of the oak gives away to floral and vanilla aromas and the colour deepens. The eau-de-vie becomes increasingly mellow, the bouquet richer and the taste less sharp. Now the flavour known as “rancio” appears.

Appearance of “rancio”

“Rancio” is characterised by notes of mushrooms, damp undergrowth and walnut oil—complex and specific aromas that develop during the long barrel ageing and increase in intensity with the years.

Experience has shown that the different crus have a different potential for extended ageing: for example, eaux-de-vie from the “Champagne” crus are well-suited to extended ageing.

Chemical changes : Evaporation, oxidation, balance

Vieillissement du Cognac : évolutions chimiquesThe ageing process includes many different phenomena :

● Substance transfers via :

– extraction, diffusion ;

– evaporation of compounds such as alcohol, water, acetaldehyde…;

– consumption of oxygen.

● Chemical changes :

– oxidation, with formation of aldehydes ;

– achievement of equilibrium between ester and acid or aldehyde and acetal ;

– reactions between compounds in the eau-de-vie and compounds extracted from the wood.