Most Canning sites will recommend beans are to be canned using only a pressure cooker. My family has been canning beans for generations using the following method. The key to home canning is sterilization.
Ensure all jars and lids are washed in hot soapy water and allow jars and lids to sit in boiling water for ten minutes. This ensures they are sterilized.
Wash green and yellow beans in cold water and cut into 1 – 1.5 inch pieces.
Bring beans to a boil for 3 minutes. A pasta pot or a blanching pot work well for this. Drain beans and place immediately into ice water.
10 cups green beans
9 cups yellow beans
3 cups diced celery
3 cups onions sliced in rings
2 (19 ounce) cans of kidney beans drained and rinsed
Mix all vegetables together in a large bowl. Mix until each spoonful contains a mix of all the vegetables. Pack into sterilized jars leaving about 3/4 inch from the bottom of the jar rim.
Bring the brine mixture to a boil, remove from heat and pour over the packed vegetables in the jars leaving ½ inch space from bottom of the jar rim. Wipe the rim then cover with new sterilized sealer lid and rim.
Place jars in a boiling canner ensuring jars are fully submerged in the water. Boil for 15 minutes. Remove jars and allow to cool at room temperature. Do not touch the lids at this point. Count the lid pops to know the lids have sealed.
Jars that do not seal should be placed in the fridge. Allow to sit for a couple days to absorb the flavours. The three bean salad will keep for a couple of weeks. Sealed jars should be dated and used within a year.