Connoisseurs have long been familiar with Louis XIII, the Grande Champagne Cognac composed of 1,200 eaux-de-vie ranging in age from 40 to 100 years. However, even these cognoscenti will be pleasantly surprised by a discovery made only a few years ago, when maître de chai Pierrette Trichet, the only woman to serve as cellar master for a major Cognac house, took note of one particular barrel in the Chai André Hériard Dubreuil on the Rémy Martin Estate at Merpins, France. The spirit contained within had a slightly elevated alcohol level, and its unusually pronounced aromas of wild mushrooms, nuts, gingerbread, and mint intrigued Trichet, who carefully monitored this cask until it was ready for bottling. At that time, she decided not to bottle this example with the standard Louis XIII but to showcase its individuality by releasing it separately. Unlike Louis XIII, which is the epitome of Rémy Martin’s signature floral style, Louis XIII Rare Cask Cognac (www.louis-xiii.com, $15,000) abounds with fruit notes, including black cherry and currants, and warm caramel overtones that lead to a long, lemony finish. Unfortunately, because this remarkable Cognac came from a single cask, only 30 of the black-crystal Baccarat decanters in which it was bottled have been allocated to the U.S. market; and of these only a few remain available for sale.