Ecosystems
An excerpt from Jeffrey Morgenthaler's blog found at the link below.
"The process is simple, and somewhat strange. Put simply: take a bunch of new spirit, straight from the second run of the still (where the “heart” of the distillate is captured) and let it sit until it’s done; two years for VS, four for VSOP, and six for XO or Napoleon. The strangeness is the little ecosystem that thrives in the aging cellars; you see, there is a loss due to evaporation that Cognac endures at the rate of about 3% per year, known lyrically as “the angel’s share”. This evaporation inside the cave feeds a black mold found only in Cognaçais cellars; it very literally exists because of the Cognac fumes. Tucked up into that mold are centuries worth of spiders’ nests, which are left to further scary-up the cellars because the spiders will in turn eat their favorite meal: a type of worm that feeds on oak barrels. Left unchecked, the worms would devour the barrels and expose the Cognac. However, thanks to the microsystem inside the cellar, the worms are harvested by the spiders and the Cognac is safe, resting comfortably for up to (but generally no longer than) 55-70 years in its gently-toasted French oak chamber. "
http://www.jeffreymorgenthaler.com/
"The process is simple, and somewhat strange. Put simply: take a bunch of new spirit, straight from the second run of the still (where the “heart” of the distillate is captured) and let it sit until it’s done; two years for VS, four for VSOP, and six for XO or Napoleon. The strangeness is the little ecosystem that thrives in the aging cellars; you see, there is a loss due to evaporation that Cognac endures at the rate of about 3% per year, known lyrically as “the angel’s share”. This evaporation inside the cave feeds a black mold found only in Cognaçais cellars; it very literally exists because of the Cognac fumes. Tucked up into that mold are centuries worth of spiders’ nests, which are left to further scary-up the cellars because the spiders will in turn eat their favorite meal: a type of worm that feeds on oak barrels. Left unchecked, the worms would devour the barrels and expose the Cognac. However, thanks to the microsystem inside the cellar, the worms are harvested by the spiders and the Cognac is safe, resting comfortably for up to (but generally no longer than) 55-70 years in its gently-toasted French oak chamber. "
http://www.jeffreymorgenthaler.com/