The Côtes des Bar marks the transition between the plains of Champagne and the rolling slopes of Burgundy. The soil in the Côte des Bar is closer to that of Chablis — Kimmeridgian marl topped by Portlandian limestone — than it is to the vineyards near Epernay and Reims, which is composed mostly by Cretaceous chalk. Unlike in Chablis, however, producers in the Aube specialize in Pinot Noir.