Editing Cognac (section)

===Aging===
Once distillation is complete, it must be aged in Limousin oak casks for at least two years before it can be sold to the public. It is typically put into casks at an [[alcohol by volume]] strength around 70%.<ref name="saveur22"/> As the cognac interacts with the oak barrel and the air, it evaporates at the rate of about 3% each year, slowly losing both alcohol and water (the former more rapidly, as it is more volatile).<ref name="saveur22"/> This phenomenon is called locally ''la part des anges'', or "the angels' share". When more than fifty years pass in the oak barrel, the cognac's alcohol content decreases to 40% in volume.<ref name="saveur22"/> The cognac is then transferred to "large glass bottles called bonbonnes", then stored for future "blending."<ref name="saveur22"/> Since oak barrels stop contributing to flavor after four or five decades, longer aging periods may not be beneficial.<ref name="saveur22"/>