Pick your green beans, avoid beans that have blemishes or rust spots, choose beans that are tender, and crisp when snapped.
Rinse green beans thoroughly then strain. Trim off ends, string if beans are a string variety, and snap into 1 to 1 and 1/2 inch (bite-sized) pieces.
Place pressure canner on stove-top and fill with rack and hot water, water level should be 2 to 3 inches deep. Turn burner on medium heat to keep water at 140 degrees Fahrenheit. Fill a kettle with water and bring to a boil.
Wash Mason jars and lids in hot soapy water. DO NOT boil the lids. Canning lid guidelines changed in 2014 and boiling the lids can affect their ability to seal. You do not need to sterilize lids or jars as long as you’re processing jars for 10 minutes or longer (which you definitely are when pressure canning). Place freshly washed jars on a clean towel on the counter.
Fill Mason jars with green beans to a 1-inch headspace (space from the top of the green beans to the top of the jar). Add 1/2 teaspoon salt to pint jars or 1 teaspoon salt to quart jars (salt is optional but does provide better flavor).
Pour just off the boil water over the top of the green beans until the liquid level reaches the 1-inch headspace.
Use a canner bubble/headspace tool (or ruler if you don’t have a headspace tool) to remove air bubbles by running it between the glass and outside of the food. Remeasure your headspace and add extra water if needed.
Use a damp cloth and wipe the rim of your glass jar clean. This helps to ensure there’s nothing that will inhibit a seal from forming. Place lid and canning band on and tighten to fingertip tight (over-tightening canning bands can cause lids to buckle). Place in the prepared pressure canner.
Place lid on the pressure canner and allow to vent for 10 minutes. Process at 10 pounds of pressure if you’re 1,000 feet below sea level and if 1,001 feet above sea level use 15 pounds, start timer when pressure is reached (weight should be rocking and hissing). Process for 20 minutes for pint jars or 25 minutes for quart jars. Remove from canner following pressure canning protocol
Allow jars to cool for 12 to 24 hours before removing bands and checking seals. Then store in cool area out of direct sunlight.