Canning Mashed Potatoes Facts and Alternatives

Mashed potatoes in a bowl next to fresh potatoes
Home canning mashed potatoes is not recommended due to their texture and the presence of dairy products. A safe alternative to canning mashed potatoes is freezing them. It is also possible to pressure can diced potatoes to preserve a product that can easily be turned into mashed potatoes. 

What is the Best Way to Preserve Mashed Potatoes?

Freezing mashed potatoes is the best way to preserve them and the only recommended method deemed safe by food preservation authorities. It does not affect the flavor, and it is a safe and easy method of long-term preservation.

  1. To freeze mashed potatoes, cook and cool the mashed potato mixture.
  2. Shape mashed potato “patties” out of the mashed potato mixture and store each “patty” between two sheets of parchment paper.
  3. Stack the parchment-wrapped patties into a labeled, airtight freezing container and place it in the freezer.

How to Reheat Frozen Mashed Potatoes

Reheating frozen mashed potatoes is easy! Frozen patties may be fried without thawing. They can also be heated on top of a double-boiler or roasted in the oven until they reach 165°F. For extra-delicious reheated mashed potatoes, stir in some fresh sour cream and serve it as a phenomenal side dish!

Fried mashed potato patties on dinner plate
Fried mashed potato patties

Is it Possible to Can Mashed Potatoes?

There are some rebel canning recipes for canning mashed potatoes, but the safety of the product is questionable due to the thickness of mashed potatoes. The USDA does not recommend canning mashed potatoes due to the starch and thick consistency, which can inhibit proper heating.

Do Potatoes Need to Be Pressure Canned?

Yes – pressure canning is preferred for low-acid foods like vegetables and meat because it kills harmful bacteria that cause food poisoning. These bacteria, such as Clostridium botulinum, can survive the temperature of boiling water used in water bath canning. However, pressure canning raises the temperature inside the canner to 240 degrees Fahrenheit, which is hot enough to kill these bacteria.

Canning Alternative for Mashed Potatoes

An alternative to canning mashed potatoes is to can diced potatoes. When potatoes are canned in small pieces, they have a much greater surface area, which allows heat to penetrate more evenly throughout the jar eliminating harmful bacteria. Pressure-canned potatoes can be easily heated and mashed to make mashed potatoes in minutes!

Diced potatoes on cutting board
Diced potatoes

How to Pressure Can Diced Potatoes

Any type of diced potato can be pressure canned including new potatoes, white potatoes, russets, red potatoes, sweet potatoes, and Yukon Golds. Follow these steps to preserve your favorite potato varieties:

  1. Peel potatoes and dice them or cut them into 1-inch cubes. You must cut them up as the heat may not penetrate a whole potato fully, and bacteria may survive in the pocket in the middle.
  2. Reduce the starch content as much as possible by rinsing or soaking the potatoes in salted cold water.
  3. Once you’ve prepared the potatoes, put them in a large pot of cold water with a few teaspoons of salt and bring them to a rolling boil. Cook for 5 to 10 minutes until the potatoes are firm but not mushy.
  4. Wash all canning jars and equipment in hot, soapy water and rinse well. Sterilize canning jars by placing them in boiling water for 10 minutes.
  5. Prepare your pressure canner by filling it up with water to the manufacturer’s recommended level. Heat the water on medium-high heat until it reaches a simmer.
  6. Meanwhile, fill your pint jars or quart jars with the prepared diced potatoes. Leave 1-inch headspace at the top of each jar.
  7. Add boiling water to each canning jar, covering the potatoes and maintaining 1-inch headspace.
  8. Remove any air bubbles by tapping the jars gently or using an air bubble remover tool.
  9. Clean the jar rims with a clean, damp cloth to remove any debris. Apply the canning lids on the jars and add the canning rings. Screw the bands on the jars until fingertip tight.
  10. Place the jars in the canner using a jar lifter. Ensure they are not touching each other or the sides of the canner.
  11. Close and lock the canner lid, following the manufacturer’s instructions. Let the canner vent for 10 minutes to remove any air from the inside.
  12. Once the canner is vented, add the weight or gauge to the canner, and bring the pressure up to the recommended level for your altitude as follows:

Recommended process time for potatoes in a dial-gauge pressure canner:

Altitude (ft)0 – 2,0002,001 – 4,0004,001 – 6,0006,001 – 8,000
Pints ( 35 mins)11 lbs12 lbs13 lbs14 lbs
Quarts (40 mins)11 lbs12 lbs13 lbs14 lbs

Recommended process time for potatoes in a weighted-gauge pressure canner:

Altitude (ft) 0-1,0001,001 +
Pints (35 mins)10 lbs15 lbs
Quarts (40 mins)10 lbs15 lbs
  1. Process pints for 35 minutes and quarts for 40 minutes.
  2. When the processing time has finished, turn off the heat and allow the pressure to drop naturally to zero. Refrain from trying to quick-release the pressure, as this can be dangerous.
  3. Remove the weight or gauge and wait an additional 10 minutes before opening the canner lid.
  4. Remove the jars carefully from the canner using a jar lifter, and put them on a towel or cooling rack. Let the jars cool for 12 to 24 hours.
  5. Remove the screw bands from the jars and inspect the seals. Sealed jars will have firm lids that do not flex up and down when pressed.
  6. Label and store sealed jars in a cool, dry place away from direct sunlight and humidity. For any unsealed jars, reprocess or refrigerate and use the contents within two days.
Mashing diced potatoes in a bowl
Mashing canned diced potatoes

Can You Can Mashed Potatoes in a Pressure Cooker?

No – canning is never safe in pressure cookers. It is vital to follow safe canning techniques and recommended processes, including tested canning recipes when home canning food.

The United States Department of Agriculture (USDA) has recommended against electric pressure cookers being used for canning, and now we have our own data showing that they just don’t hit the high temperature needed for canning safely at our altitudes.”

– Cathy Merrill of Utah State University faculty

Can You Water Bath Can Mashed Potatoes?

No, mashed potatoes cannot be safely water bath canned because they are a low-acid food and contain dairy products, which makes them susceptible to botulism.

Are Potatoes Worth Canning?

Yes! Canning potatoes has many incredible benefits:

  • Canned potatoes have a shelf life of 1-2 years.
  • Canned potatoes save time and effort and can be quickly added to soups, stews, and more!
  • Canning potatoes preserves a large harvest or allows you to stock up during sales.
  • Home canning reduces packaging and food waste.
  • Properly canned potatoes retain their texture, flavor, and nutritional value.
  • They can be stored at room temperature, freeing up valuable freezer and refrigerator space.
Canned sweet potatoes being topped with water in canning jars
Canned sweet potatoes

Where to Store Canned Potatoes

Follow these guidelines when storing canned potatoes:

  1. Choose a cool, dry place with a stable temperature between 50°F – 70°F.
  2. Store the jars off the floor and in airtight containers to prevent access by pests.
  3. Store them in a dry environment with low humidity to prevent corrosion of canning lids.
  4. The storage area should be dark, as exposure to light can cause discoloration and nutrient loss.

What Is The Shelf Life Of Canned Potatoes?

Home-canned potatoes should be used within 1-2 years because the quality of the potatoes may begin to degrade over time. As the potatoes age, they may lose some texture, flavor, and nutritional value.

To ensure the best quality, eat your canned potatoes within the first year of canning and always inspect the jars before use, looking for signs of bulging lids, discoloration, or foul odors. Discard the contents immediately if you notice any indications of spoilage.


Adam was fascinated from an early age by his father's car and his mum's kitchen. His love of home food preparation stems from her. From baking to roasting and freezing to canning, he has always followed the lessons she taught him all those years ago.

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