Rinse the rice and cook it in a pot with the 4 cups of water remaining. Cook it for 40 minutes with the cinnamon stick until the rice is extremely soggy and can’t absorb more water. Let it chill and remove the cinnamon stick.
Take to the blender and blend the rice, the milk, the condensed milk, the salt, the ground cinnamon and the nutmeg. Blend in high speed for 5 minutes. You can add more milk if your feel that the chicha is too thick.
Top with extra sweetened condensed milk and a sprinkle of ground cinnamon. (optional)