Wash and peel potatoes.
Place in ascorbic acid solution to prevent darkening, do not leave them in long.
Cut potatoes into ½-inch cubes and drain.
Boil a pot of water, put the potatoes into the water for 2 minutes and drain again.
For whole potatoes, boil for 10 minutes and drain.
Add 1 teaspoon of salt per quart to the jar, if desired.
Fill jars with hot prepared potatoes, leaving no more than 1-inch headspace.
Cover hot potatoes with fresh boiling water, leaving 1-inch headspace.
Place jars in the pressure canner, lock the lid, and bring to a boil.
Vent steam for 10 minutes, then close the vent.
Process for 35 minutes for pints and 40 minutes for quarts at 10 lbs of pressure.
Turn off the heat and let pressure return to zero naturally.
Wait 10 minutes then remove jars and place on a dishtowel to cool.
Check lids and reprocess any jars that did not seal.
Label jars after they have cooled.
