A porous cordierite substrate and a method of forming a porous cordierite substrate including providing a fiber that includes at least one cordierite precursor material and providing at least one organic binder material. The fiber and the organic binder material are mixed with a fluid. The mix of fiber, organic binder material and fluid is extruded into a green substrate. The green substrate is fired to enable the formation of bonds between the fibers and to form a porous cordierite fiber substrate.