Okay, I broke down and looked it up.
Masa harina is masa fresca which has been dried and pulverized, and has the texture of wheat flour used in baking. Masa fresca is made from field corn which has been soaked in slaked lime. Add water to masa harina and you've got masa for tortillas, tamales, etc.
Cornmeal is coarse (like farina) and hasn't been treated with slaked lime (which loosens the hulls and makes the niacin which is in corn easier for humans to digest).
While it is not recommended to substitute cornmeal (or wheat flour,for that matter) for masa harina, the recipe I was making didn't suffer for it. I was making a sweet corn pudding/porridge, but other recipes would definitely be affected in a bad way.
MM
Last edited by MissMuffins; 01-19-2015 at 08:57 PM.
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