Wash your jars, lids, and bands in hot, soapy water. Rinse well and keep them warm.
Peel the potatoes and cut them into uniform pieces (cubes or slices). Place the cut potatoes in a large pot of water to prevent browning.
Boil the potatoes for 2 minutes, then drain.
Pack the hot potatoes into warm jars, leaving 1-inch headspace. Add salt if desired.
Pour boiling water over the potatoes, maintaining the 1-inch headspace. Remove air bubbles and adjust the headspace if necessary.
Wipe the jar rims with a clean cloth, place the lids on top, and screw on the bands until fingertip tight.
Place the jars in the pressure canner. Follow your canner's instructions for venting and processing. Process pints for 35 minutes and quarts for 40 minutes at 10 pounds pressure (adjust for altitude if necessary).
After processing, turn off the heat and let the canner depressurize naturally. Remove the jars and place them on a towel to cool for 12-24 hours. Check seals before storing.