Prepare your jars and lids and keep them hot until needed. Check the air vent and overlock on the canner lid to make sure they are not blocked.
Put 2 quarts of cool water in a large bowl and stir in 2 teaspoons of sea salt. Stir it up until it dissolves.
Scrub potatoes with a stiff brush under running cold water. Peel them or leave the peel on.
If you have small potatoes that are 1 to 1½ inches in diameter you can leave those whole. Larger potatoes need to be cut into ½ to 1 inch cubes. As you cut them, put them into the salt water.
Par-boil potatoes (optional): cook cubes in boiling water for 2 minutes, cook small whole potatoes in boiling water for 10 minutes.
Drain the potatoes and loosely pack the potatoes into the hot jars, leaving 1 inch headspace.
Add salt, if desired, using ½ teaspoon in pints, ¾ teaspoon in 1½ pints and 1 teaspoon in quarts.
Add boiling water leaving 1 inch of headspace, releasing trapped air.
Wipe the rim of the jar with a clean dry cloth or paper towel and add lids and rings, tightening finger tight.
Add water to the canner, adding a splash of white vinegar if you have hard water. Put the jars in the canner.
Seal the lid and turn the heat to high.
Allow the canner to vent for the specified length of time for your canner.
Put the regulator on the air vent and bring it up to pressure.
Once it has reached the required pressure, start your timer.
Process pints at 10 pounds pressure for 35 minutes, process 1½ pints and quarts at 10 pounds pressure for 40 minutes. Don’t forget to adjust the processing pressure for your altitude.
When the processing time is up, turn off the heat and allow the pressure to return to zero.
Once the pressure is zero, remove the regulator and wait another 5 to 10 minutes before unsealing the lid.
Remove the jars from the canner and allow to sit undisturbed for a minimum of 12 hours.
After 12 hours, check the seals, wash and label the jars, and put them away.