Cut the stems off of the beans. Cut the beans into 1- to 2-inch pieces before freezing or leave the beans whole and, if desired, cut the frozen beans into pieces just before using. Bring a large pot of water to boiling. Allow 1 gallon of water per pound of green beans. Fill a large bowl with ice water. Boil beans for 3 minutes. Cool the beans quickly by plunging them into ice water. After the beans have cooled, drain them from the ice water. Pack the drained beans into freezer containers or bags; compact the beans, leaving a 1/2-inch headspace. Lay bags flat; add bags or containers to freezer in batches to make sure they freeze quickly. Leave space between bags or containers so air can circulate around them. Use frozen green beans within 8 to 10 months.