The muffins can be frozen for up to 2 weeks. Thaw the muffins and reheat before serving.
Stone-ground cornmeal is tastier and more nutritious than regular, steel-milled cornmeal because it contains some of the husk and germ. The germ contains a small amount of fat, so the stone-ground cornmeal can spoil. It should be stored in the refrigerator for no longer than four months. Bob's Red Mill is a widely available brand.