How to Can Potatoes

When summer canning is underway, most people don’t include potatoes. That’s reasonable. Potatoes are available all year long, they’re cheap to buy and they can be stored in a cool place for a fairly long time without the need for special preservation techniques. But for those growing their own produce, canning the harvest is an easy way to store homegrown spuds for use well beyond the few months a potato might last (even in the best of conditions). Canned potatoes can also come in handy at dinnertime when the precooked potatoes make speedy mashed potatoes or hash browns a snap.

If your canning experience has been mostly about pickles and jam, potatoes may require some new equipment. Like many vegetables, potatoes are low-acid, which means they can't be processed in a water bath like pickles, jams or other canning projects with sufficient acidity. Instead, we look to pressure canning. While the temperature of a standard water bath peaks at 212 degrees F, the pressurized steam in a pressure canner can heat to 240 degrees F (or higher), which is the magic number needed to kill the bacteria that leads to botulism without the help of the bacteria-killing acid found in water bath-appropriate foods.

Pressure canning is not difficult but requires attention to be successful. Once the prescribed pressure has been reached, that pressure must be maintained until the process is completed.

An added benefit of this method: Low-acid canned goods retain much of the flavor found in fresh produce and often have a much longer shelf-life than high-acid canned goods.

Prepare Potatoes for Canning

Gather the materials needed for canning (Image 1). Wash and peel potatoes and cut to the desired size. Depending on size and preference, potatoes may be quartered, cut into 1-2 inch cubes or left whole (Image 2). Place the cut potatoes in a pan of cold water while you finish preparing the rest of the potatoes. The cold water will keep the potatoes from oxidizing. Once you have all the potatoes cut, drain the water and fill with fresh, clean water (Image 3).

Prep Jars and Blanch Potatoes

Bring a large pot of water to a boil. This will be the water you will use to pack the cut potatoes in the canning jars. Make sure you have enough water to fill the jars (Image 1). Sterilize your canning jars, lids and rings. Keep them warm until they are ready to be packed (Image 2). Bring the pot of cut potatoes to a boil and let it boil for about two minutes. Blanching will release some of the starch in the potatoes, reducing clouding and water loss in the canned produce (Image 3). After the two minutes are up, remove from heat. Drain and discard the water.

Pack the Potatoes

Place a 1/2 teaspoon of salt in the bottom of each pint canning jar (use a full teaspoon for quart jars). Salt does not impact the canning process and is added only for flavor (Image 1). Fill jars with blanched potatoes, leaving 1 inch of headspace (Image 2). Pour boiling water into each jar to cover potatoes (Image 3). Cap jars with lids and bands.

Load the Canner

Place the rack at the bottom of the canner. Fill the canner with a couple of inches of water and turn on the heat. Place the jars into the canner (Image 1). Leave space between the jars. You may need to adjust the water level in the canner. The water should come up the side of jars at least two inches (Image 2).

Process the Potatoes

Line up the lid with the body of the canner. Most canners will have an arrow or a "V" on the lid to help you line it up and then, twist the lid in place (Image 1). Tighten the wing nuts in pairs on opposite sides to ensure the lid is on level (Image 2). The potatoes need to be processed in a weighted pressure canner at 10 pounds pressure for 35 minutes for pint jars and 40 minutes of quart jars if you live at an altitude of 1,000 feet above sea level or less (Image 3). Consult your pressure canner instruction manual for equipment-specific canning instructions or the National Center for Food Preservation for specific processing times for your altitude.

Cooling

When the processing time is complete, turn off the heat. DO NOT remove the lid. The canner needs to depressurize. Allow the pressure canner to cool for an hour. Once the canner has cooled, open up the canner and remove the jars (Image 1). Let the jars cool for 12 hours or overnight. Check the seal (the center of the lid should be down and have no flex or give at all) and then label with the date. Jars that did not properly seal should be refrigerated and used first.