Step 1

In a large bowl, stir together the masa harina and salt. While stirring with a silicone spatula, gradually add the water, then stir until the masa is evenly moistened. Transfer the masa to the counter and knead until smooth and putty-like, about 1 minute. Pinch off a small piece, roll it into a ball and flatten it; if the edges crack, knead in more water, 1 tablespoon at a time, then test again.

Step 2

Transfer the masa to a large sheet of plastic wrap and wrap it tightly. Let rest at room temperature for at least 15 minutes or up to 1 hour to allow the masa to hydrate. Meanwhile, cut out two 8-inch rounds from a clean plastic grocery bag (alternatively, cut a gallon-size zip-close plastic bag into two 8-inch squares).

Step 3

Divide the masa into 12 portions (each about 40 grams). Using your hands, roll each into a smooth ball and set on a plate. Lightly spritz with water and cover with a kitchen towel. Set a 10- or 12-inch nonstick skillet over medium-low and a 10- to 12-inch cast-iron skillet or griddle over high. Heat both until the cast-iron pan is very hot, about 10 minutes.

Step 4

While the pans are heating, line a large plate with another kitchen towel and spritz the towel with water a few times to dampen. Open the tortilla press and lay one of the plastic rounds on the plate. Set 1 masa ball in the center and flatten it slightly with your hand. Cover with the second plastic round. Close the press and press down firmly on the handle. Open the press, rotate the masa in the plastic 180 degrees and press firmly again; the tortilla should be about 6 inches in diameter. If the pans are not yet fully heated, leave the tortilla in the plastic until they are.

Step 5

Peel off the top plastic round. Using the plastic on the bottom, flip the tortilla onto the palm of your hand and slowly peel away the plastic. Using both hands, carefully place the tortilla in the nonstick skillet and cook until the edges begin to dry and the tortilla releases easily from the pan, about 20 seconds. While the tortilla is cooking, press another ball of masa; set aside.

Step 6

Using a wide metal spatula, flip the tortilla and cook until it releases easily from the pan, about 30 seconds. Now transfer the tortilla without flipping it to the cast-iron pan. Immediately, quickly and lightly drag the metal spatula across the tortilla 2 or 3 times; the tortilla should begin to puff. Cook until the edges begin to brown on the bottom, 15 to 20 seconds, then flip the tortilla and cook, pressing lightly on the edges, until lightly charred on the second side, about 30 seconds.

Step 7

Transfer the tortilla to the prepared plate (it will deflate) and enclose in the towel. Cook the second tortilla in the same way and press another; stack the tortillas as they are done and keep them wrapped in the towel (make sure the towel remains lightly moistened with water). Continue until all of the dough has been pressed and cooked. If the masa balls begin to dry out as they sit, lightly spritz them with water. Serve warm.