Rather than being double-distilled as cognacs are, most armagnacs — including Cognac Lhéraud’s — are distilled only once. Distillation occurs in a traditional armagnac pot beginning in November or December and ending in February. Lhéraud armagnacs are aged in Limousin and Monlezun oak barrels, during which time evaporation concentrates the alcohol. As a result, armagnacs, like cognacs, are gradually cut with water, or petites eaux, a weak mixture of water and Armagnac, to bring their final alcohol level down to 40 percent or 80 proof.
The Bas-Armagnac Vieil 1955 was distilled in 1955 and aged in oak until it was bottled in 2014 (59 years old).