It's named after a holy city and was kept inside a single Sufi brotherhood for nearly a century before it broke out onto every street corner in the country.
Café Touba is coffee roasted and ground together with djar (grains of Selim, a peppery spice), giving it a warm, peppery, almost incense-like flavor. Street vendors pour it from kettles into small paper or plastic cups for a few coins on corners across Senegal.