Masa harina, which translates in Spanish to “corn flour,” is not to be confused with cornmeal or American corn flour – they are NOT interchangeable in tamale making. Masa harina is essentially dehydrated, powdered corn dough that just needs water to reconstitute into a pliable dough again. Corn flour or cornmeal, on the other hand, are just plain, untreated ground corn that will not rehydrate into a dough.