Canning green beans with boiling water involves pre-sterilizing the jars, cleaning the green beans and heating water to boiling. The next steps are adding the ingredients to the jars and using a pressure canner to seal them.
To pre-sterilize the canning jars just before filling them, place them in a deep pot. Fill the pot with water until it's 1 inch above the jar tops. Bring the water to boiling, and boil the jars for at least 10 minutes. Remove from heat, but keep the jars inside the hot water until ready to fill them.
Pour 2 quarts of water into a pot, and bring it to a boil. Meanwhile, rinse the green beans, and shake off the excess water. Use a sharp knife to trim off both ends of the beans. Pull out the string from the back of each bean, and then cut it into 2-inch pieces.
Remove a canning jar from the hot water, and tightly pack the cut green beans inside. Pour 1/2 teaspoon salt into pint jars and 1 teaspoon salt into quart jars. Pour the boiling water over the beans until 1 inch of headspace remains.
Carefully tap each jar to remove any air bubbles, and wipe the rim. Place the lid and band on each jar, tightening by hand. Place each jar in a pressure canner, and process at 10 pounds pressure for 20 minutes for pints. For quarts, process for 25 minutes.