Before you tour the cognac houses, try Pineau des Charentes, the local apéritif that almost nobody outside the region knows. It is made by blending unfermented grape must with cognac, stopping the fermentation and leaving a sweet, mellow drink that runs between 16 and 22% alcohol. Served chilled with oysters or foie gras, it is one of those regionally specific pleasures that rarely survives the journey home.
Most distilleries produce their own Pineau and sell it in their shops. The maisons Ragnaud-Sabourin and Château de Beaulon are particularly well regarded for their Pineau production. Wine bars in the old town also serve it by the glass — typically cheaper than any of the cognac options and a more honest introduction to how the Charente drinks at home.