Soak beans. The night before, soak the beans in cool water.
Drain and rinse beans. Drain and rinse the soaked pinto beans. Place them in a large pot (8-10 quart).
Cook beans. Add enough water to the pot so the beans are covered with water plus 2 inches. Place over medium heat and allow the beans to come to a boil. Cover and reduce the heat to low and simmer for 30 minutes.
Prep canner. Prepare your pressure canner by adding the rack and 3 inches of water to the pot (or follow your manufacturer's recommendations). Add 2 tablespoons of white vinegar (this prevents mineral deposits from collecting on the jars). Place over medium heat and allow it to come to a gentle boil.
Prep jars and rings. Place the lids and rings in a pot with hot water and simmer (don't boil). Wash the jars with hot soapy water. Fill them with hot water (so they don't crack when filled with the hot beans).
Drain beans. Once the beans have simmered for 30 minutes, drain them and set aside.
Prep hot water. Bring a pot of water to a boil. (This will be for filling the jars later)
Fill jars with beans. Drain the jars of the hot water. Using a funnel and ladle, fill the jars with beans leaving a 1-inch head space. Top with 1 teaspoon of salt if using quart jars or ½ teaspoon of salt if using pint jars. Fill the jars with fresh hot water leaving a 1-inch headspace. Using a wooden chopstick or plastic knife (not metal), remove as much air and bubbles as you can. Refill with water so there’s a consistent 1-inch headspace.
Place lids on top. Place the lids and rings onto the jars.
Process in pressure canner. Using a jar lifter, place the jars into the pressure canner making sure there’s enough space between jars. Place the lid on the canner, making sure it's sealed. Cook on high heat until a steady stream of steam is being released. Let the steam vent for 10 minutes. Set your gauge to 10 pounds for a weighted gauge (or 11 pounds for dial) and let the canner come to pressure. Adjust for altitude if you live above sea level. Once it hits the pressure, set the timer for 75 minutes for pint-sized jars or 90 minutes for quart-sized jars. Continue to monitor the pressure so it doesn’t go below. If it does, bring it back up to pressure and restart the timer.
Release pressure. When the time is up, turn off the heat and allow the pressure gauge to hit zero before releasing the steam. Release the steam and carefully remove the lid, tilting the lid AWAY from you so the steam doesn’t hit your face.
Rest jars before removing. Allow the jars to sit for 10-15 minutes before removing them from the canner.
Cool and check seals. Place the jars on a cooling rack and let them cool overnight. Check for a seal after 24 hours. Immediately use any unsealed jars and store the properly sealed jars for up to 18 months. (check your lid’s manufacturer’s recommendations for storing.)