If you’ve ever whipped up a pot of creamy and delicious mashed potatoes, you’ve likely asked yourself, “How long do mashed potatoes last?” In this article we will answer exactly that as we break down the ingredients in mashed potatoes and why refrigeration is key to keeping your fluffy and delicious mashed potatoes kept at the best quality.
Table of Contents
- How Long Does Mashed Potato Last in the Fridge?
- How Long Do Mashed Potatoes Last in Freezer?
- How Long Do Mashed Potatoes Last at Room Temperature?
- Can Old Mashed Potatoes Make You Sick?
- How Can You Tell If Mashed Potatoes Are Bad?
- Is It Safe to Reheat Mashed Potatoes?
- How Do You Store Mashed Potatoes?
- FAQs
- Storing Potatoes With Care Is Highly Important…

How Long Does Mashed Potato Last in the Fridge?
How Long Do Mashed Potatoes Last in the Refrigerator?
Mashed potatoes last in the fridge for about 3-5 days, give or take.
Because most mashed potatoes are simply made up of potatoes, milk, butter, seasonings, and possibly either buttermilk vs sour cream –depending on preference – most mashed potatoes will last only a few days. This is because the mashed potatoes were made fresh with fresh ingredients.
How Long Do Instant Mashed Potatoes Last in the Fridge?
Instant mashed potatoes will also last about 3-5 days in the fridge.
Although many instant or boxed potatoes may contain preservatives to maintain freshness, the truth is that once your instant potatoes are made, they will still only last about 3-5 days in the fridge.
As always, check for signs of spoilage before eating and throw out any instant potatoes that look, smell, or seem otherwise unsafe for consumption.
How Long Can You Keep Cooked Potatoes in the Refrigerator?
That depends.
Just as when a person asks, “How do you like your steak cooked?“, a question like how long a person can keep “cooked” potatoes in the fridge could yield a variety of answers.
That’s because “cooked potatoes” could refer to a variety of potato types, and because of this, it is difficult to pinpoint exactly how long each potato dish will last.
Popular potato dishes that contain cooked potatoes such as mashed potatoes or potato salad tend to have a short shelf life because they may contain dairy and eggs.
However, even without the addition of these ingredients, you may find that cooked potatoes in their simplest form, such as boiled potatoes, still only last anywhere from 3-5 days.
Thus, the consensus here is that most cooked potatoes of varying types will last stored in your fridge for a little less than a week or so before needing to be pitched.

Can I Eat Week Old Mashed Potatoes?
You shouldn’t.
Surprisingly, it isn’t only the milk, butter, and other dairy products found in mashed potatoes that pose a threat to your health when left in the fridge too long. Potatoes themselves have been associated with mass illness for ages. If you eat old potatoes you run the risk of ingesting harmful bacteria that could have dramatic negative impacts on your health.
How Long Do Mashed Potatoes Last in Freezer?
As long as your mashed potatoes contain plenty of fat, they should easily last about a month in the freezer.
That’s because the cream, butter, and milk fat in mashed potatoes act as a protective barrier to protect the dish from freezer burn. Thus, it is important that you be sure not to neglect to add these ingredients if you plan to freeze fresh mashed potatoes.
How Long Do Mashed Potatoes Last at Room Temperature?
Mashed potatoes can sit out no longer than two hours.
Remember that mashed potatoes are perishable and can be risky to eat once they’ve gone bad. Therefore, it is best to refrigerate your mashed potatoes within 2 hours of preparation to avoid potential food poisoning.

Can Old Mashed Potatoes Make You Sick?
Yes, they can.
In fact, consuming old potatoes puts you at high risk for botulism which is a severe form of food poisoning. The symptoms of botulism include:
- Vision Problems
- Muscle Weakness
- Droopy Eyelids
- Slurred Speech
- Difficulty Breathing
How Can You Tell If Mashed Potatoes Are Bad?
How to Tell If Mashed Potatoes Are Bad?
Mashed potatoes that are bad will usually have the fat separating from the liquid. In addition, the potatoes may change in color and texture and might have a sour odor to them.
If you see mold or any of the previously mentioned signs occurring with refrigerated mashed potatoes, be sure to toss them.
Due to the risks, we don’t recommend doing a taste test, especially if your potatoes have been in the fridge for more than 3-5 days.
Is It Safe to Reheat Mashed Potatoes?
You can reheat mashed potatoes, but be careful.
It isn’t so much the reheating method that is a safety issue when it comes to potatoes as much as it is an issue of cleanliness and storage.
If the potatoes weren’t properly cleaned to begin with, you could be dealing with contaminated potatoes whose bacteria will only continue to grow whilst cooking.
On the other hand, if you’ve cooked your potatoes but have left them out to sit for extended periods of time, your potatoes could end up breeding bacteria.
And though you may think you may be able to cook off the bacteria, this may not be true with potatoes. Even the hottest potatoes may still contain bacteria if they were left out to sit before reheating.
How Do You Store Mashed Potatoes?
Mashed potatoes should be placed in an airtight container in the refrigerator as soon as possible after being made. This will ensure that the potatoes don’t develop any bacteria from having sat out too long.
In addition, always get rid of your potatoes before five days are up. You may need to get rid of them sooner than that if you notice the separation of liquids, foul odors, changes in color, or the development of mold.
FAQs
How long are leftover potatoes good for?
Leftover potatoes are generally good for anywhere from 3-5 days.
How long can potatoes stay in the fridge?
Cooked potatoes can, and should, stay in the fridge for no longer than 5 days.
Why do my leftover mashed potatoes taste sour?
If your leftover potatoes taste sour, take notice. It likely means that your mashed potatoes have gone bad, even if you made them the night before.
Remember, severe cases of botulism have long been associated with the consumption of “bad” potatoes. Consuming sour mashed potatoes isn’t worth the risk.
Storing Potatoes With Care Is Highly Important…
After making fresh mashed potatoes, you’ll want to be sure to store them with care. Neglecting to properly store and refrigerate your mashed potatoes after making them could lead to food poisoning or botulism. Therefore, you should never eat any potatoes showing signs of mold, change in color, texture, or other signs of spoilage as doing so could have devastating impacts on your health.