How to taste Cognac
The first effect of taking some of our sample into the mouth is the possibility of confirming by way of retro-olfaction the presence of certain aromatic notes as the mouth's warmth helps their perception.
As for the previous phase prudence must be observed in taking only a small quantity each time due to the presence of alcohol at a relatively high concentration. The parameters of "balance" between acids, sugars (including alcohol), astringency and aromatic elements are thoroughly documented and universally accepted.
For Cognac and for spirits in general the position is less well established. Firstly acidity is less important even if the chemical reactions during maturation produce acids. Phenolic acids and the other tannin compounds provide bitterness whose unpleasant effects are reinforced by the sharpness of alcohol. The same alcohol, a minimum of 40% by volume, contributes to the sugar taste which attenuates our perception of acidity and bitterness but not without the sharpness mentioned above which many refuse. All in all it is quite confusing.
Jacques Puisais, founder of the "Institut du Goût", uses a phrase which we find very appropriate; maturation "assagit l'eau-de-vie" which translated freely says that aging calms spirit, softens it. Effectively the aging process does reduce the fiery sensation. In younger Cognac the judicious use of a little sugar helps to round the spirit. Quality cognac will coat the inside of the mouth without attacking the gums and it will leave a long-lasting sensation of warmth and unctuousness. Here it is the equal of highly reputed wines. The increased concentration in acid and bitter compounds in extremely old Cognacs result in a drier sensation which is more than compensated for by the increased aromatic complexity.
If a few final pieces of advice are sought after; take your time and compare different samples while noting down as many impressions as possible, they will be the base of your reference library.
Glossaire: Emile Peynaud & Jean Ribéreau-Gayon - anciens professeurs de "l'Institut d'œnologie" de Bordeaux..
retro-olfaction – the passage of aromas to the nose via the mouth tannin compound – chemical composite containing tannin
phenolic acid – aromatic elements which form part ot the tannin compounds