As the old adage goes, 'All Cognac is brandy, but not all brandy is Cognac.'
Brandy is produced in many parts of the world but only brandy made in the 'Appellation d'Origine Controlee' area surrounding the town of Cognac in France is permitted to be called Cognac.
Cognac's history is deeply linked to the Charente river that runs through the region, and well before the spirit was produced, the Charente, an easy navigable river, was used to transport goods to the northern parts of Europe, including wines of course.
The region is divided into many parts (Crus), each with their own unique terroir, capable of producing eaux de vie of varying characteristics and quality. Those held in highest esteem include Grande Champagne, Petit Champagne and the Borderies regions where, primarily, the Ugni Blanc grape is grown and then, this highly acidic and thin wine is then left to rest few a few weeks before undergoing double-distillation in copper pot stills. It is then aged at least two years in French oak barrels from either Limousin or Troncais.
The labelling of Cognac is their guide to quality and also signifies it's length of time ageing in the barrel, where the eau de vie will take on the flavours imparted from the wood. In order, they are 'VS' (very special), 'VSOP' (very special old pale), 'XO' (extra old) and 'Extra'. The higher up the order you go, the more expensive the Cognac.