The additive that gives New Orleans-style coffee its roasted, earthy flavor is chicory.
More precisely, the roasted and ground root of the chicory plant is blended with coffee. Chicory root has a deep, toasted flavor that can add body and a slightly bitter, earthy character; some descriptions also compare its taste to chocolate. It may be used to stretch coffee, but in New Orleans it became a defining regional flavor rather than merely a substitute.
The tradition grew during the American Civil War, when Union naval blockades restricted access to the port of New Orleans and made coffee scarce. Louisianans began adding roasted chicory root to their remaining coffee supplies. The practice continued after the shortage ended and became closely associated with local café culture, including Café du Monde’s signature brew.
Chicory is not cocoa, cinnamon, or vanilla. It comes from a flowering plant in the daisy family, Cichorium intybus. Its roots can also be used as a coffee substitute on their own, while New Orleans coffee typically combines chicory with actual coffee beans. The familiar café au lait pairs this blend with scalded milk and is traditionally enjoyed with beignets.