What is the difference between whisky and cognac?

Whisky comes from grain, cognac from white grapes. Scotch starts with water and malted barley; cognac starts with wine from five permitted grape varieties from the Charente.

With whisky, starch is first converted into fermentable sugars, after which yeast turns them into alcohol. With cognac, the sugar is already in the grape. The cahier des charges of the AOC Cognac names colombard, folle blanche, montils, semillon and ugni blanc; in practice ugni blanc is by far the most planted, because it stays acidic and low in alcohol and therefore distils well.

Scotch may be distilled to just under 94.8 per cent and the law does not prescribe a still shape. Cognac must go twice through a copper alambic charentais over an open flame.

For cognac the regulations also fix the dimensions: the still may be at most 30 hectolitres and the charge at most 25 hectolitres. After the second run the eau-de-vie may not be stronger than 72.4 per cent at 20 degrees. Distillation must be finished by 31 March after the harvest. For Scotch only the upper limit of 94.8 per cent determines the leeway, and that is so much higher that more styles are possible.

Scotch must mature for at least three years in Scotland, in oak casks of at most 700 litres. Cognac must mature for at least two years, uninterrupted and exclusively in oak.

For Scotch, besides oak, the law also prescribes the place: everything happens within Scotland, in an excise warehouse. For cognac the emphasis lies on the wood and on uninterrupted maturation; the regulations speak of vieillissement without interruption, exclusively in oak casks. Neither may ultimately be weaker than 40 per cent in the bottle.

VS stands for at least two years of maturation, VSOP for at least four years and XO for at least ten years. XXO is used from fourteen years.

The statements refer to the youngest eau-de-vie in the blend, just as an age on a whisky bottle indicates the youngest whisky. XO used to be six years; since 2018 it has been ten. Whisky has no such letter designations: the bottle shows a number in whole years, or no age at all. So both systems say something about the floor of the blend, not about the average.

For Scotch, the Scotch Whisky Regulations 2009 apply. For cognac, the cahier des charges of the protected designation of origin applies, overseen by INAO and the Bureau National Interprofessionnel du Cognac.

Both are protected geographical indications: the name may only be used for a product made in the designated area according to the laid-down method. Whisky as a generic name is not protected and is made all over the world; Scotch and Cognac are protected. So anyone who distils grapes in the Netherlands and puts the spirit in oak makes a grape brandy, but never cognac.