Hominy or nixtamal is dried maize (corn) kernels which have been treated with an alkali of some kind. The traditional U.S. version involves soaking dried corn in lye-water (sodium hydroxide or potassium hydroxide solution), traditionally derived from wood ash, until the germ is removed. Mexican recipes describe a preparation process consisting primarily of cooking in lime-water (calcium hydroxide). In either case, the process is called nixtamalization, and removes the germ and the hard outer hull from the kernels, making them more palatable, easier to digest, and easier to process. It also alters the flavor in a way that many consider to be an improvement. Commercially available canned hominy often has a strong and unique odour. The process dates back nearly 10,000 years in ancient Mesoamerican cultures. It affords several significant nutritional advantages over untreated maize products. It converts some of the niacin (and possibly other B vitamins) into a form more absorbable by the body, improves the availability of the amino acids, and (at least in the lime-treated variant) supplements the calcium content, balancing maize's comparative excess of phosphorus. Some recipes using hominy include menudo (a spicy tripe and hominy soup), pozole (a stew of hominy and pork, chicken, prawns, or other meat), hominy bread, hominy chili, casseroles and fried dishes. Hominy can be ground coarsely to make grits, or into a fine mash (dough) to make masa, the dough used to make tamales and tortillas.