Common Characteristics

• All cognacs start out as a white wine from the Charente vineyards with a particularly high acidity and low alcohol content. The unique cognac character comes from a two-time distillation in traditional copper Charentais stills, followed by aging in oak casks for a minimum of two years to produce a dark spirit with a subtle vanilla aroma. Cognac must include at least 90 percent Ugni Blanc, Folle Blanche and Colombard grapes and have an alcohol content between 40 and 72 percent. The eventual value and character of a cognac depends on the region it comes from within the Charente and the period of aging, with more mature cognacs commanding a higher price.

Cognac Classes

• Determine the quality of a cognac by checking the label. The cheapest cognacs -- between $30 to $50 at the time of publication -- carry a V.S. rating, which stands for "very special" and refers to cognacs whose youngest brandy in the blend is at least two years old. Slightly more illustrious but roughly the same price are the V.S.O.P. -- or "very special old pale" cognacs -- which are at least four years old. Either of these cognacs can be used in a cocktail mix without causing consternation and represent a large portion of what you find in the stores. Much more exclusive are the elite Napoleon or X.O. Extra Old Cognacs which are at least six years old and cost between $60 to $100, at the time of publication, with coveted blends costing much more. Complex, voluptuous and expensive, these cognacs demand a thin, round-bottomed glass, appreciation and nothing more.

Exclusive Editions

• The finest, priciest cognacs come either from a separate, darker cellar for mature brandies that master blenders refer to as “Paradise,” or they go into bottles outlandishly decorated in fine gemstones. In celebration of its 250th anniversary, Hine distillers released a limited edition, single-barrel 1953 vintage that commands a five-figure price tag, while Martell bottled just 1,997 L’Art de Martell to commemorate the 1997 handover of Hong Kong to China. The oldest cognacs sold at auction go for the price of a luxury car, such as the 1858 Croizet vintage from Grande Champagne that fetched $156,700 in 2011. Eclipsing all is the 100-year-old Henri IV Dudognon Heritage Cognac, sold in a bottle decorated in 24-carat gold, platinum and 6,500 diamonds, which can by yours for around $2 million.

Prized Regions

• Within the Charente, cognac production is confined to six growing areas. To source the most expensive and prestigious cognacs, focus on those from Grande and Petite Champagne, and the Borderies, which produce light brandies destined for long aging, characterized by a smooth, round texture and distinctive violet notes. Prices range from three to four figures at the time of publication. Less prestigious are those from Fins Bois, Bons Bois and Bois Ordinaires, noted for their grape and maritime flavors and quick aging. Most cost around $60 at the time of publication, but exceptional vintages are just as expensive as those from more illustrious regions. Typically, cognacs from the Grande Champagne sub-region draw the most admiration and command the highest prices. Look for the specific origin on the label. Only those that are 100 percent from the region are allowed to claim their exclusivity.