Making the basic tortilla is simple, at least in theory. First a dough is made. To do this, the maize kernels are parched and cooked briefly in a mixture of unslaked lime and water. This step (see nixtamalization) loosens the husks, increases the nutritional content of the grain, and ensures that a flexible flat bread can be made. Then the corn is ground into a dough called masa in Mexico (a commercial product called masa harina, a flour made from the prepared kernels, can be mixed with water to make tortillas when corn is unavailable). The dough is shaped between the hands, or patted out on a flat surface, or stamped out with a special press. The tortillas are then cooked on a hot, ungreased griddle. They should be speckled with brown, and puff up when turned, but remain soft and pliable—rather like an Indian chapati.