Homemade Corn Tortillas

1. Combine the masa mix and warm water in a medium bowl, mixing until a soft dough forms. You can use a wooden spoon for mixing, but you will have better results if you use your hands. Turn the dough out onto a floured surface and knead until it is smooth.
If the dough seems dry, add more water, a tablespoon at a time, as necessary.
2. To form the tortillas, one at a time, pinch off small handfuls (about 3 tablespoons) of the dough and roll each one between the palms of your hands into a ball. Cover the dough balls with a damp cloth as you form them, to keep them from drying out.
3. Cut a quart-size resealable plastic bag open down both sides, to form a rectangle. Use the bag to line a tortilla press as you shape the tortillas, so they do not stick: Lay one side of the plastic over the bottom of the press, place a ball of dough in the center, and fold the other side of the plastic over the dough. Shut the top of the tortilla press firmly down on the dough to shape the tortilla. (See Note.)
4. Heat a griddle until hot. Place a tortilla on the griddle and cook for 1 1/2 minutes. Using a spatula, flip it over and continue to cook, flipping it occasionally, until both sides are covered with small brown spots. Transfer to a plate and cover with a kitchen towel to keep warm while you cook the remaining tortillas, stacking the finished tortillas on the plate. Serve immediately.