Sort the Beans - Lay the beans in a shallow layer on a cookie sheet, pie pan, platter or clean kitchen towel.Then remove and discard any bad beans (broken, off-colored or shriveled), debris, pebbles, rocks or foreign material.
Rinse the Beans - Place the sorted beans in a colander or strainer and rinse them under cold running water.
Soak the Beans - Transfer the beans to a large bowl or pot and add water to about 3/4's full. Soak the beans for 5 hours. Every 45 minutes to an hour, drain the beans, discard the water, and refill the soaking container (with the beans) with fresh water.
Once the pinto beans are done soaking, drain out and discard the water.
Cooking the Beans - In a large pot add hot water so that it's about half full. To the water, add salt and heat the pot on low heat (just enough heat to simmer the beans).
To the pot, carefully add the soaked and drained pinto beans. After adding the beans, if the water level is lower than 3/4's full, add just enough water to bring up the level to 3/4's full.
Stir the beans periodically as they cook. Let simmer until the beans are tender (about 2-1/2 hours). Keep a close eye on the pot of beans as it simmers because the water level will decrease. Have a large cup of water nearby to refill the pot of beans before the water level gets too low.
When the water level in the pot decreases by about 2 inches, add more water to bring the level back up to 3/4's full. More water may need to be added 2 or 3 times while the beans are simmering.Continue to watch the pot of beans closely to make sure that there is still water in the pot (don't let the pot run out of water or the beans will burn).
After 2 hours and 10 minutes check the beans to make sure they're tender. Use a large slotted spoon to scoop out a couple of beans and transfer them onto a plate. When they're cool enough to eat, give them a taste to make sure they're tender. If not, continue to simmer the beans.
If the beans are tender, during the last 15 to 20 minutes of cooking them, let the water decrease to about 1/2 full without refilling it. Continue to watch the pot of beans closely to make sure that there is still water in the pot (don't let the pot run out of water or the beans will burn).
After 2-1/2 hours of simmering the beans (or longer if needed), remove the pot from the heat and set it on an unused burner.