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How Long are Leftover Mashed Potatoes Good For?

If you love mashed potatoes, you’re not alone!

They’re one of the most popular side dishes in the country, pairing perfectly with a vast array of meats, veggies, and other foods. Plus, they’re easy to make, affordable, and delicious.

But how long are mashed potatoes good for? Once you make them, how long can you safely leave them on the counter, in the fridge, and in the freezer?

Here’s what you need to know:

Do Mashed Potatoes Go Bad?

Unfortunately, they can.

If mashed potatoes are left out too long, pathogen bacteria can develop. The most common type that develops on mashed potatoes is Bacillus Cereus [1], although other microbes can also form depending on what other foods the potatoes are mixed with.

Eating bad mashed potatoes can cause food poisoning, resulting in vomiting, diarrhea, and other gastrointestinal issues.

Depending on the extent of the spoilage and the number of potatoes eaten, you could experience symptoms for days or even more than a week. If you suspect you’ve eaten bad mashed potatoes, check with your doctor.

mashed potatoes

To identify whether or not mashed potatoes have gone bad, do the following:

  1. Smell the potato – Spoiled potatoes will have a bitter, moldy scent.
  2. Look at the potato – Dark spots indicate spoilage.
  3. Taste the potato – Spoiled potatoes have a sour, tangy taste.

The smell and sight tests should be all you need. If you’re feeling adventurous and want to taste mashed potatoes you find suspicious; only try a tiny bite.

Also, keep in mind that sometimes potatoes can go bad without displaying any obvious signs.

That’s why it’s so important to follow the time and temperature requirements detailed below. They’re your most important safeguard against food poisoning.

How Long Do Leftover Mashed Potatoes Last?

The answer varies depending on how they’re stored. Generally, the colder they’re stored, the longer they’ll last. Their average lifespan is as follows:

  1. Two hours – uncovered or covered at room temperature
  2. Three to five days – covered in the refrigerator
  3. Ten months to a year – covered in the freezer

Here’s a closer look at each.

How Long Can Mashed Potatoes Sit Out?

They can sit out for about two hours before potential problems start to develop.

Note the two-hour rule applies when the potatoes are sitting inside at room temperature. Significantly colder or warmer temperatures can reduce the time before the potatoes start to go bad.   

Mashed potatoes are what’s called a “holding hot food [2].” Once made, they should maintain a temperature at or above 140° F. After about two hours, room-temperature air will cool the dish’s internal temperature down to where the food should be put away or reheated.

While the mashed potatoes themselves can go bad after two hours, the most common culprits are typically ingredients that have been mixed in. Milk-based products, such as butter and milk, often spoil much quicker than the potatoes themselves.

(Quick tip: Do you use instant mashed potatoes? An unopened box remains safe to use for 12 to 18 months, provided you store it in a cool, dry, and dark pantry.)

How Long Do Mashed Potatoes Last in the Fridge?

You can store mashed potatoes in the fridge for up to five days. The refrigerator must be 40° F or below [3].

Make sure you put the potatoes in the fridge within two hours after cooking them. Otherwise, you might end up refrigerating a dish where bacteria have already started to form.

At the same time, make sure you’re not storing potatoes in the refrigerator when they’re too hot. They should have an internal temp of 70° or below before you put them in the fridge.

Do you need to cool down hot potatoes quickly so you can store them? Put them in a container no deeper than three inches. Then, place the container in a sink filled with a small layer of ice water. Twirl the mashed potatoes with a spoon to help disperse the heat.

When storing potatoes in the refrigerator, put them in either a sealed container or a Ziploc baggie. Make sure to release as much excess air as possible. Tupperware or similar containers typically work great. 

How Long Can Mashed Potatoes Last in the Freezer?

You can store mashed potatoes in the freezer for a year or even longer, as long as the temperature inside remains below 0°F.

Freezing will protect against bacteria and spoilage but doesn’t always preserve the taste. The longer you keep mashed potatoes in the freezer, the more their flavor and texture are negatively affected. They can become grainy, mushy, and bland.

To freeze mashed potatoes, place cup-sized scoops on a baking sheet. Put the sheet in the freezer until the mashed potato scoops are frozen. Then, put the frozen scoops in freezer-safe baggies, which you can then stack. You can also use plastic pints, such as the ones found at your local deli.

How long are mashed potatoes good for as far as taste is concerned?

For best results, you’ll want to use them within one month of freezing. Any longer, and they likely won’t taste as fresh (although they’ll still be safe to eat).

Thawing Frozen Potatoes

Thawing your frozen mashed potatoes is easy but does take some time.

First, you’ll want to place the frozen potatoes in the refrigerator for about 12 hours. Then, you can reheat them using any of the following methods:

  1. Stovetop
  2. Microwave on 50% power
  3. Slow cooker

If your reheated mashed potatoes are too watery, try mashing a single new potato and mixing it in with your leftovers. If they’re too dry, add small amounts of cream until they soften.

You may like: What To Eat With Mashed Potatoes?

Bonus Tips About Mashed Potatoes

What to Do with Leftover Mashed Potatoes

Mashed potatoes are a staple on Thanksgiving or any day for that matter. What do you do with the leftover mashed potatoes?

We have compiled some different uses for your leftover mashed potatoes.


How to Make Mashed Potatoes

Mashed potatoes are a classic Thanksgiving dish that can be tricky to make.

This video will provide you with easy and delicious mashed potato recipes that can be prepared in minutes.

Whether it’s for a holiday meal, or just to enjoy on the side, these potatoes are sure to please!

Final Thoughts

How long are mashed potatoes good for? At room temperature, they’re good for two hours. In the fridge, they can last five days. When frozen, they’re best within a month but can last a year.

Mashed potatoes are terrific with a wide variety of different meals, and now that you know how to store them safely, you have far greater flexibility as to when you can use them!

I’m Jennifer Schlette, a Registered Dietitian and Integrative Nutrition Health Coach. I love cooking, reading, and my kids! Here you’ll find the healthiest recipes & substitutions for your cooking. Enjoy, and be well, friends!

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