Final answer:
Removing lees from base wine before distillation in Cognac production generally leads to a purer final product rather than enhancing the richness of flavor and mouthfeel. It is during the aging process in oak barrels that Cognac gains its complexity and rich character.
Step-by-step explanation:
In Cognac production, the removal of the lees — which are the dead yeast cells and other particles that settle out of the wine after fermentation — is a critical step. Contrary to the assertion of the question, removing the lees before distillation does not make for a richer flavor and mouthfeel; it actually results in a cleaner, more pure distillate. The lees can add body and complexity to the wine if left during maturation, but in the case of distillation for Cognac, the presence of lees would lead to off-flavors when the wine is heated up and the compounds react.
Lees may contribute complexity to a still wine but are generally removed before distillation in the production of spirits like Cognac to ensure clarity and purity of the final product. During the aging process, however, compounds from the toasted oak of the barrels can enhance the flavor profile and mouthfeel of the Cognac, leading to rich and nuanced spirits.