The first thing you need to know about Cognac is that it's a grape brandy made in the Charentes region of France, centre around the town of Cognac.
Brandy itself came from the Dutch name "brandewijn", or burnt wine as in the distillation process that the wine goes through; the wine itself is not actually burnt of course.
Today, Cognac is produced using grapes from a number of different sub-regions in the Charentes including Grande Champagne, Petite Champagne, Fins Bois, Bons Bois and Borderies. Of these, Grande Champagne is often considered the best region and many houses will choose to declare this on the bottle.
The production process
Cognac is double distilled, using traditional pot stills with a capacity of up to 25 hectolitres, from white wine. The wine is usually made from Ugni Blanc grapes although you will also find Colombard, Folle Blanche and a few others.
The distillation can take place any time between the end of vinification (when wine is made) to the 31st of March of the following year.
After the first distillation, the liquid is usually at 27-29% alcohol and are called "low wines". After the second distillation, the resulting liquid becomes a 70% alcohol white spirit called eau-de-vie. Normally, each eau-de-vie is aged separately before being blended and bottled. Some producers, however, also choose to blend before ageing or not at all.
It is the eau-de-vie, after ageing in oak barrels, which becomes Cognac.
The different categories
By law, Cognac must be aged in French oak barrels for at least two years but beyond that they can go on ageing for hundreds of years. And unlike wine, Cognac is aged above ground in a "Chai", or Cognac warehouse, rather than cellars.
There are three main age categories for Cognac - VS, VSOP and XO. VS (Very Special) indicates that the youngest eau-de-vie in the blend is at least two years old, while VSOP (Very Special Old Pake) requires four and XO (Extra Old) needs a minimum of six.
Some houses also produce other styles such as single vintage, reserve (four years), Napoléon (six years) and Hors d'âge (six years) where the ageing of the eau-de-vie generally extends to beyond the legal requirement.
How to drink Cognac
There are no hard and fast rules about drinking Cognac and, like whisky, it can be enjoyed neat or in cocktails.
As a guide however, the younger spirits, VS and VSOP, generally work better in cocktails. As VS and VSOP are still relatively young, the alcohol isn't completely tamed during the time spent ageing in barrels so they can be quite harsh to drink neat. Even with a little water or ice, there generally isn't enough complexity. However, the relative lack of flavour is perfect for blending with other ingredients.
When you move up to XO and beyond, it's recommended that you drink the spirit neat, with ice (the larger the better) or a little water. After significant ageing, the spirit becomes more complex with fruit, floral and nut notes which are better expressed when drunk unadulterated. Cognacs that are XO or older are also significantly more expensive.
It's also important to note that each house has a different style of Cognac and some are better suited to drinking neat when young than others.