Cooking teacher: Lima beans generally need about an hour of boiling to reach the proper degree of doneness  The precise amount of time it takes depends on size: larger beans require a longer cooking time than smaller beans do  It is important that lima beans not be overcooked since overcooking robs beans of many of their nutrients
Undercooking should also be avoided, since undercooked beans cannot be completely digested
Lima beans that are added to the pot together should be as close to the same size as possible if they are to yield their full nutritional value.