Is that obvious, redundant? Maybe so.
However, until 1909 when a decree protecting the delimited area was signed, this was not all that clear. The decree claims that only the spirit made with eaux-de-vie from the protected zone and permitted grapes are entitled to the name Cognac. They must be distilled and aged following specifically authorised techniques, respecting the double distillation process in a copper alembic, and aged in oak barrels for a minimum period of time.
Thus, all Cognac is brandy but not all coñac, kognac, or brandy is Cognac.
Not all Cognacs are alike:
With a rich clay soil, a softly tempered sea climate, and generous amounts of sunlight, the Charente valley enjoys a climate specifically favourable to cultivating vines. It covers over 200, 000 acres along the Charente river and may be distinguished by six different viticultural areas, or 'crus'.
Enjoying specific climate and soil, each region produces different and complimentary qualities of eaux-de-vie. The areas form a circular belt surrounding Cognac, and the eaux-de-vie loose sharpness and gain in body as they move further from the center.
The blending, or "marriage", of these distinct qualities will confer to each Cognac its individual, unique, character.
Only a long period of maturing in oakwood casks allows an eau-de-vie to become a Cognac.
The oak wood, quite porous, keeps the Cognac in permanent contact with the naturally humid or dry air of the cellars while losing some of its alcoholic content. This evaporation leaves a dark hallow over the walls of the town, poetically called 'The Angels Share'. A microscopic fungus - the 'torula compniacensis Richon', develops thanks to the humid air of the cellars. The angels over Cognac 'drink' each year some twenty million bottles per year, making them the second largest market for Cognac after the United States!
After the double distillation, the Cognac starts to mature at a maximum of 72% alcohol. Time will help it lose over a third, reaching not less than 40% in order to be sold. The ageing process follows three main phases:
The 'extraction', during which the wood transfers to the eau-de-vie most of its tannin, boisé and taste. The newly distilled colourless eau-de-vie takes on some of the wood's tannins, naturally attaining its golden amber color. Each Cognac house decides on the respective length of stay in young and old casks according to the desired quality: The younger wood will transmit far more tannin to the eau-de-vie than the older.
The 'ageing', also called degradation or hydrolysis, is the period during which the eau-de-vie flattens. After two to three years of maturing, the eau-de-vie reaches qualities proper to consumption. But if allowed more time, the Cognac gains in complexity, perfume, aroma and taste. Bouquet and mellow reach their finest after fifty years.
Finally, the 'oxidation' gives the eau-de-vie its final bouquet and golden shade. Once transferred into glass, the Cognac is no longer in contact with the air or wood, and stops maturing. It remains immutable. Each Cognac house stores its oldest Cognacs in demi-johns in remote cellars known as 'Paradise'
Of Arabic origin, it is thought that the copper alembic, originally used to produce medicinal essences or perfumes, reached France at the time of the crusades; it has remained the same for the past three centuries. Copper is not only an efficient heat conductor but also plays a purifying role.
For its first distillation, the unfiltered wine is brought to boil in the copper pot. Since alcohol evaporates faster than water, alcoholic vapors may be collected in the onion dome shaped cowl and in the swan neck, which slows the rectification process of the flavors, before passing into the long serpentine condenser coil. Vapors condense to the contact of the cooler and turn into a liquid known as 'brouilli'.
This brouilli, with an alcoholic content of 27 to 30% vol., is distilled a second time in a process called the 'bonne chauffe'. The distiller's key task is then to choose the moment when to isolate the 'heart' of this second distillation, extracting the 'head' and the 'tail' in the process.
This distillation process is a delicate and slow one. It lasts for approximately twenty four hours and requires the constant care of the distiller. It usually begins in November and is conducted day and night for several months. The rule binds it to stop at the latest at the end of March. Distillation is a key factor to confer the Cognac its distinctive character. Its secrets are handed over from generation to generation.