The Armagnaçaise have two advantages over their rivals; the Cognaçaise operate on such a large scale that they do not generally offer brandies from individual estates and unlike the Armagnaçaise, they did not until the mid 1960’s have the legal right to date their brandies. For the past 40 years every French restaurant worthy of a Michelin star has offered a range of single estate single vintage armagnacs. In 1973 when Janneau started to market single vintage armagnacs, Etienne Janneau said, "It was our only weapon against the Cognaçaise, the individual vintages created our image of quality".
Vintages are controlled by the BNIA and if required dates may be checked by the carbon dating process. Armagnacs, distilled in the years when there were atmospheric nuclear tests can be measured by the level of carbon 14 in the spirit and to guarantee further quality, the BNIA has ruled that no individual spirit can be sold unless it is at least ten years old. The growers have 5 years in which to declare the brandies they propose to sell as individual brandies.
Armagnac is a product whose quality derives from sandy soil, albeit a very particular type. The region forms part of what was once a deep channel between the older rocks of the Pyrenees and the Massif Central. As the sea ebbed and flowed it built up irregular layers of sand and clayey rubble from the Pyrenees to the sides of the channel, the region which now forms the Bas armagnac and Tenareze. The climate is hotter than in Cognac and grapes ripen more fully but the breezes from the Bay of Biscay ensure the summer never gets too hot. The taste of armagnacs is automatically associated with the flavour of prunes and plums but strangely enough those grown further to east in Tenareze which combines chalk and sand develop more floral qualities. The many individual qualities found in the Gers Department provides today the excellent fruity brandies we call armagnac.