The distiller, or professional distiller, is an unrivalled technician whose perfect knowledge of the Charentais copper pot still and various distillation methods enables them to produce Cognacs tailored to the specifications of négotiant firms. They tend to own a wide range of pot stills of various shapes and sizes, ranging from a dozen to around fifty, which they use to provide a distillation service for winegrowers who do not own a boiler. Year after year, this alchemist ensures careful, precise monitoring from one estate to the next, always placing an emphasis on excellence. They often work primarily or exclusively with one négotiant firm whereby they know the ins and outs of specifications for pre-blends and pouring-off temperatures. This discreet technician may also have their own vines and venture into aging or even selling their own wine spirits.