This is how you nixtamalize dried field corn. Flour corn is best for this, but you can also use dent or flint corn, even popcorn. Sweet corn doesn't work.
10gramscalcium hydroxide, "cal" in Mexican markets
1gallonwater
Instructions
Cover the corn with the water and stir in the cal. Bring to a rolling boil, stir, then drop to a bare simmer. Let the corn simmer, partially covered, for at least 30 minutes.
Take a kernel out and bite it in half: You want to see it mostly cooked, but with a white, chalky center still. This can take as long as an hour, but start checking at 30 minutes. When the corn hits this stage, turn off the heat, stir once more, cover the pot and let it sit overnight.
The next morning, use your fingers to sift the kernels in the now-sludgy water. You want to rub them well to remove the slimy pericarp. Pour the contents of the pot into a colander to drain. You will want to clean your sink's screen as the sludgy stuff will clog it.
Rinse out the pot, then return the corn to it. Cover with fresh, cool water. Rub the kernels some more to get most of the pericarp off. (Here's a short video of the process.) Rinse in the colander one more time. You now have nixtamal.