Spread a kitchen towel on the counter. Using your jar lifter, remove the warm jars from the canner, drain, and line up on the towel.
Drain your potatoes and discard the cooking water.
Fill jars with the hot potatoes. Add 1/2 teaspoon canning salt to each pint jar, or 1 teaspoon to each quart (salt is optional but adds a lot of flavor). Add fresh hot water to the jar, leaving a 1-inch headspace.
Run your bubble popper through the jar to release any bubbles that may be caught in between the potatoes.
Use your magnetic lid lifter to lift lids out of the warm water, center lid on the jar, and screw on band until it is fingertip tight.
Using the jar lifter, place the jars into pressure canner leaving space in between them. Once the jars are all in canner, adjust the water level per your pressure canner's instructions. If adding water, use the hot water from your large pot.
Follow the directions for your pressure canner and process pints for 35 minutes, and quarts for 40 minutes at 10 pounds of pressure for at altitudes of less than 1,000 feet. Adjust processing time for your altitude if necessary.
When processing time is complete, turn off the heat and allow the pressure canner to cool for about 1 hour.
When the pressure canner has cooled, spread a kitchen towel on the counter, unlock cover and remove by tilting lid away from you so that steam does not burn your face.
Use a jar lifter to lift jars from canner and place on the towel. Allow the jars to cool for 12-hours. You should hear the satisfactory "ping" of the jar lids sealing.
After 12-hours, check to be sure jar lids have sealed by pushing on the center of the lid. The lid should not pop up. If the lid flexes up and down, it did not seal. Refrigerate jar and use up within a few days.
Remove the screw on bands and wash the jars. Label and date the jars. Store your jars in a cool, dark place, and use within 12 months. Yields 9 pints or 7 quarts.