Cognac, like brandy, is distilled wine. (Actually, cognac technically IS brandy, just special extra high quality.) Wine is not always made from grapes, of course, and thus neither is brandy always from grape wine.
True cognac comes from the west of France and is made from a particular variety of white grape called Ugni Blanc. This kind of grape produces a rather bland wine which is not particularly interesting as a wine, but since the wine is going to be distilled, aged and blended anyway, that doesn't matter. The point is, this wine makes a good "base" for producing Cognac.
The wine is then distilled (during the winter) in copper stills, and the resulting colorless, POTENT liquid is then placed into oak casks to age.
[To "distill" means to heat the wine until it changes into its gaseous state (when water does this, we call its gaseous state "steam") and then cool it back down by running the vapor through a series of coils (copper tubing in this case) until it returns to liquid form and drips out the end of the coil into a receiving container. A post dedicated to distilling is coming up, so I won't go into more detail here. The main thing to remember here is that, in distilling fermented liquids, the whole point of distilling is to raise the alcohol content percentage of the liquid. Basically, alcohol has a lower boiling point than water does, so you heat the wine up only to a point where the alcohol "boils" but not the water. The water part of the wine is thus left behind and only the alcohol part "boils off" and is collected at the other end of the cooler coil. So the liquid collected at the other end is really flavored alcohol mostly. Sorry, I said I wasn't going into it that deeply but it just escalated on me.]
"Regular" undistilled wine might have a, say, 7% alcohol content, but if you choose to distill that wine, the alcohol content in the resulting liquid is much higher. With cognac, this is about 40%. Incidentally, "proof" is always double the alcohol content of any distilled alcoholic beverage. So, in the above example, the cognac would be "80 proof."
The distilled liquid is left in the oak casks for a minimum of two years, but sometimes for decades. The latter cognac would cost you a bit more than the former. Heh. Anyway, it absorbs color, flavors, and aroma from the oak and the result is cognac. Not quite finished yet, though: most often, cognacs of different ages and regions are blended (by experts in the craft) before it is bottled. This is how the various signature styles and tastes of different brands is achieved.
Tomorrow: how to choose a cognac and how to drink cognac. You can't just dump the stuff in a coffee cup, you know! Is this cool, or what?
