Here’s How Long Mashed Potatoes Last In The Fridge (And What To Do w/Them)

Mashed potatoes are a kitchen staple, and pretty much everyone loves them.

The trouble is, sometimes we can go overboard and make way too much, or we just get a whole bunch leftover.

So how long can you keep them in the fridge ? Well, it turns out the fridge is pretty lenient with us, and there’s a lot we can do with leftover mashed potato !

Let’s take a look at how long they last in the fridge, how to tell when they’ve gone off, and how to reuse them

mashed potato

So how long do mashed potatoes last in the fridge ?

In optimal storage conditions mashed potatoes can last 3-5 days in the fridge.

This is in an airtight container, and it’s best if it’s a shallow and wide one, so the food cools evenly.

Know that mashed potatoes can go bad, but they can still be kept for a reasonably long amount of time in the fridge.

This doesn’t mean you should cook in bulk and store it for a week, but it’s helpful to know what to do with them if you’ve got some leftovers.

Never leave them on the counter overnight

The original question is about leaving mashed potatoes in the fridge, at a temperature as close to zero as possible.

But this needs to be said too.

Never leave mashed potatoes on the counter overnight, especially if you’ve added any dairy products to them.

This is is because bacteria and mold can and will develop fairly quickly, and your meal might just turn a little sour if the room is especially warm.

You can let the food cool on the counter for a couple of hours, but stick it in the fridge as soon as you can.

mashed potato (1)

Adding butter and milk turns them bad quicker

Adding any dairy, not just butter and milk, will make mashed potatoes that much better, luscious and just damn amazing.

But the trouble with this is that we’re adding proteins and fats, which are not stable at room temperature and especially not at high heat.

So if your mashed potato is plain, it might keep a little better.

But if it’s got any dairy – milk, Parmesan cheese, Cheddar, cream cheese, butter, anything milk-related, it really needs to get into the fridge as soon as possible.

Always store mashed potatoes in an airtight container

When storing mashed potatoes – any cooked food, actually – you should be using an airtight container.

This will help you in several ways:

  • the potatoes won’t absorb the smells from the fridge
  • they won’t dry out, but keep the moisture in
  • if they’re contaminated, it won’t spread to other foods

Whatever airtight container you store your mashed potatoes in, make sure it’s wide and shallow. This will ensure the food will cool evenly in the fridge, and you won’t get any warm spots that will go bad faster.

mashed potato (2)

You can also freeze mashed potatoes

Freezing mashed potatoes is also an option, and their texture won’t really change since they’re mushy to begin with.

All you need is enough room in the freezer, and some freezer-safe bags or containers.

Make sure to let the masher potatoes cool at least to room temp before you stick them in the freezer. If you put them in warm or hot, you’ll defrost the other foods in the freezer and raise the general temperature.

We don’t want that, we want to food to freeze as quickly as possible.

Portion your mashed taters in appropriate portions. You know yourself and your family, and how much you need for one sitting.

Once you’re done portioning the food into bags or containers, place them in the freezer and they’ll keep for up to 12 months.

Then, when you need some mashed potatoes with your food, just take out a serving and microwave it very, very well.

How to tell if the mashed potatoes went off

Of course, even with the best storage conditions mashed potatoes can still go bad, especially if you leave them for too long.

There’s a few ways you can figure out if they’ve gone off,  and here they are.

They look bad

Including moldy patches, looking glossy in some areas or being completely dried in some parts.

Mashed potatoes look great and golden when fresh. You can sort of see them glow with butter or milk or whatever you’ve added to them.

Plain mashed potatoes will look pretty much the same, whether they’re fresh or day old.

But once they start looking bad, or at least weird, you should try and remember when you made them.

mashed potato (5)

They smell bad

This goes alongside them looking bad, but not always. Sometimes the mashed potatoes can still look fine but develop an unbearable smell, coming from the fermentation process that’s already happening.

Moldy patches don’t really smell, but it’s not a good idea to give them a sniff as inhaling those spores can cause serious breathing problems.

Please note that if you’ve added any dairy, the smell might get funky faster.

And if you’ve added aged cheese or a moldy cheese, you can’t really rely on smell here.

They taste sour

Another way to see if they mashed potatoes have gone off is to taste them. I don’t recommend this, unless you’re really unsure about the previous two points.

They look right, they smell right, but you’re still not sure.

You can taste them, but only get a very, very small amount on the tip of a teaspoon. That should be enough to figure it out.

If you’re not sure after the first taste, you could still taste it, yes, but try not to eat too much.

If they’re sour or otherwise weird, put them down. It’s not worth heating them up.

You don’t remember when you put them in the fridge

It happens to the best of us. We sometimes completely forget certain foods in our fridge, and this can happen with mashed potatoes as well.

If you really, truly can’t remember when you put them in the fridge, go through the previous 3 points.

If you find anything wrong with them, discard them.

You can use leftover mashed potatoes

What do you do when you’ve got leftovers ? Reuse them, of course !

But how do you reuse mashed potatoes ?

And how old do they have to be before you throw them out ?

Well, in regards to age, as long as they’re still edible – see previous 4 points – they should be fine.

But keep in mind that once you’ve reheated mashed potatoes you shouldn’t keep them for another 3 days. Eat them right then and there, and don’t keep then any longer.

So whatever you use them as/in, make sure it’s gone in one sitting.

mashed potato (3)

You can add something to thicken them up and make patties out of them.

Potato patties are great, and they don’t always need to be just patties. You can make baked mashed potato fingers, with some cheese added in.

Another option is loaded baked potatoes, or you can just use a cake decorating attachment and form swirls with them, and then bake them. Those are especially fun for kids, and they can make it themselves.

mashed potato (4)

You can also stir some mashed potato into a cream soup to thicken it.

Something like a bacon and potato cream soup, or a leek and potato soup. Or, really, whatever kind of soup you like, as long as you think it’ll go with potato.

Know that if you’ve added cheese or cream cheese then it’s not a good idea to boil the soup afterwards. Just add in the mashed potatoes at the end, and give it a few minutes to really blend in with the rest of the food.

If you were to boil (even gently simmer) soft cheese or regular cheese they’d start to break apart and get a weird taste.

Final thoughts

Mashed potato is everyone’s first love, and we all like to have it fairly often. This is why taking care to know the food safety limits on mashed potatoes is a good thing, since it’s such a common food item.

If you’ve got any food curiosities be sure to check the related articles below, we’re always adding more food facts to make your life that much easier.