Marble and Grain™ is certified kosher by the Star-K and Mishmeres Hakashrus, headed by Rabbi Yechiel Steinmetz.  Products packaged under the Mishmeres Hakashrus label can include shechita directed by Rabbi Yechiel Steinmetz; Rabbi Aaron Teitelbaum, Av Beis Din Nirbater; and Rabbi Menachem Meir Weissmandel, Av Beis Din Nitra Monsey.