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Do Marshmallows Go Bad?

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It can be difficult to resist marshmallows on sale in the store, and if you find a great bargain and suddenly realize you have more marshmallows than you can eat in an acceptable amount of time, you might be wondering:

Do marshmallows go bad? Yes, marshmallows do go bad. However, they can last anywhere from 1-6 months after their best-by date, if stored properly. Make use of proper storing practices to ensure that your marshmallows stay fresh, and keep an eye on the expiration date.

So whether this is your first pack of marshmallows, or you have over-stocked in the pantry, here is all you need to know about whether marshmallows go bad, how to store them, and everything in between.

How Long Do Marshmallows Last?

How long marshmallows last will depend on the brand of marshmallows. Some marshmallows last for 1-2 months, and others can last for up to 6 months after their best-by date.

An unopened packet of marshmallows will last longer than a bag that has been opened. Once you have opened the bag of marshmallows, you should make an effort to eat them within a week

Most producers say it is best to eat the marshmallows within 3 days of opening.

This does not mean the marshmallows will even go bad so soon, but they will harden and not taste as great as they should.

If you know that you will not finish the marshmallows within this time, follow proper storage methods or even place the marshmallows in the freezer. This will extend their shelf life quite a bit.

While it does vary, you can get away with enjoying your marshmallows around 1 month after the best-by date. Just be sure to check for signs of the marshmallows spoiling before taking a bite.

Do Marshmallows Expire?

Marshmallows do expire, although it does take quite a while for them to spoil and go bad. Each packet of marshmallows will have a best-by date indicated on the packaging.

This is more of a guide to when the marshmallows will have their best quality, and not necessarily when they will spoil.

After this best-by date, the marshmallows might begin to lose their light, fluffy texture, and start to harden and lose their taste. They should still be safe to eat, though.

You will need to check for any signs that the marshmallows have spoiled, just to be extra sure.

If left for a very long time, there is a chance that marshmallows will expire and go bad. While they are shelf-stable, they will not last a lifetime, and it is best to discard any marshmallows which are well past their best-by date. 

The marshmallows will be fine to eat for about a month after the best-by or expiration-date if they have been left unopened. For opened marshmallows, it is best to eat them within a week of their best-by or expiration dates.

How to Store Marshmallows to Keep Them Fresh

Marshmallows now are made slightly differently from how they were initially. Nowadays, marshmallows are made from a formula including gelatin, water, and sugar. Marshmallows do have a considerably high water content, but they are shelf-stable, and they can be kept in a cool, dark environment.

You do not need to store marshmallows in the fridge, even when the package has been opened. You do need to ensure that the marshmallows are kept at just below room temperature, so a pantry cupboard is a good choice.

If you live in a warm climate and temperatures are quite high, then it might pay off to keep the marshmallows stored in the refrigerator, just to ensure that they do not melt and create a huge mess.

Unopened Bags

For unopened bags of marshmallows, you can simply pop them into the cupboard and leave them as-is. Just make sure there are no tears or openings in the packaging.

To be extra safe, you could place the unopened packet of marshmallows into a plastic bag for some extra protection.

Opened Bags

Once you have opened the bag of marshmallows, you will need to find a way to keep them sealed.

You could either place a bag sealer onto the opened part of the packet and seal it shut, or you could pour the marshmallows into a large freezer bag or plastic container.

It is really important to keep the marshmallows in an airtight container or packaging to keep them fresh. If you are placing the marshmallows into a plastic freezer bag, squeeze out any air, or the marshmallows will begin to harden.

Marshmallows pick up odors from food around them quite easily, so make sure the packaging or container you store them in is strong enough to protect the marshmallows from picking up any scents and odors that may ruin the taste.

If you want to store the marshmallows in the fridge, keep them in an airtight container.

Proper storage of the marshmallows will keep them in the best condition for longer, and ensure that they taste wonderfully fresh when it comes time to enjoy them. Dark, cool environments are ideal for marshmallow storage.

Can You Store Marshmallows in the Freezer?

You might not guess it at first, but marshmallows and marshmallow fluff actually do really well in the freezer. You don’t often hear of people freezing their marshmallows, but that is because there isn’t much of a need for it.

However, if you have a considerably large stash of marshmallows, you might want to store some in the freezer.


For unopened packets of marshmallows, you can simply pop them into the freezer as-is. There is no other prep you need to do.

If you are a bit nervous to do this, you could wrap the package in plastic wrap, or place it into a plastic freezer bag.


To freeze opened bags of marshmallows, you need to transfer them to a suitable freezer container.

It is easy to use a plastic freezer bag, as you can squeeze any excess air out, seal it shut tight, and label it with the name of contents and date of freezing. Plastic freezer bags can also be laid down flat in the freezer to save space.

You are also able to place the marshmallows into a plastic freezer container. These offer a little more protection to the marshmallows and are reusable. 

Try not to over-pack the marshmallows in the container you choose. It is also a good idea to flash-freeze them first on a tray so that when you pour them into the container for freezing, they will not stick together.

This way, you can remove a few at a time without having to defrost all of them.

Defrosting Marshmallows

Defrosting marshmallows is fairly easy. As with most other foods, it is safer to defrost the marshmallows in the fridge overnight or for a few hours.

This keeps them at a safe temperature and ensures they defrost slowly and evenly while retaining their quality.

Once defrosted, you might have slightly sticky marshmallows. If this happens, you can sprinkle some powdered sugar or corn starch over them. Shake them together to distribute the powder and this should stop the stickiness.

After being left in the fridge overnight or for a few hours, your marshmallows will be ready to use and eat.

How Do You Tell if Marshmallows Have Spoiled?

When you open a bag of marshmallows, you get a sweet and powdery aroma, and when you take a bite, the marshmallows are sugary and sweet.

If you open a bag of marshmallows and aren’t confronted with this smell, or a bite of the marshmallow doesn’t give you that satisfying sugary taste you want, it might be a sign that your marshmallows have gone bad, or are starting to spoil.

Marshmallows might also lose their taste and smell if they are kept in a moist or humid environment. These are best thrown away. You can always pick up a new batch when you visit the store again.

If stored in warmer environments, the marshmallows might also melt slightly and stick together in a bunch. It can be quite difficult to separate them and this causes a huge mess.

However, this does not necessarily mean that the marshmallows have spoiled.

Extra chewy marshmallows are another sign that they have spoiled, or that they have been kept in a less than suitable storage condition. If a marshmallow takes forever to chew, throw the whole pack away.

Sweet, sugary marshmallows will be like a homing beacon to ants and other insects. Make sure that the marshmallows are properly stored so that no bugs can get in and have a snack.

If you notice any small holes on the packaging, there is a good chance that bugs or ants have found a way into the marshmallows. It is best to just throw away a packet of marshmallows that have been munched on by bugs.

Proper storage of the marshmallows really does help to extend the shelf life, and to ensure they stay delightfully fresh.

Related Questions:

What Are Marshmallows Made of?

Little clouds of sugar, marshmallows are actually quite easy to make. They are made by mixing sugar, gelatin, and water. Air is whipped into the sugar, which gives marshmallows their light and fluffy texture, and super-sweet taste.

The sugar and gelatin are dissolved in water, and then whipped intensely to incorporate air into the mix, and after a short shaping process, you have your marshmallows.

There are two different types of marshmallows – American style and European style. The European marshmallows are a denser consistency and have more depth of flavor.

However, many people prefer light, fluffy, and sweet American marshmallows more.

Marshmallows are great to make at home, and the marshmallows you make at home can even be a mix of European and American marshmallows, so you won’t have to choose your favorite.

Does Marshmallow Fluff Expire?

Marshmallow Fluff is a delicious spin-off from the traditionally served marshmallows and is a popular pantry item in many homes.

It can be used to make some delicious desserts or just eaten from a spoon when you need a little treat.

Unopened marshmallow fluff can last for up to 8 months when stored in the pantry, in a dark and cool environment. Once again, you will need to check the best-by or expiration date on the packaging and work with that timeline as well.

Once opened, marshmallow fluff can last between 2-4 months. You can store the marshmallow fluff in the refrigerator or freeze it to extend its shelf life, and to keep its best quality for a longer period.

Once again, look for any signs of spoiling before tucking into a serving of marshmallow fluff which has been sitting in the cupboard for too long, or which has passed its best-by or expiration date.

If the marshmallow fluff smells off, looks different, or has an off taste, you should discard the bottle and pop over to the store to buy a new tub.

Can I Use Old Marshmallows?

It is better not to use old marshmallows. Not only will they not have the same taste and texture, but they might not melt as well either, which is not ideal when making S’mores and desserts.

The marshmallows will melt into a giant blob instead of melting soft and gooey.

How Do I Fix Marshmallows That Have stuck Together?

If your marshmallows have been in warmer temperatures and have started to stick together, you can save them.

To do this, pour some powdered sugar or cornstarch over the marshmallows. Close the bag and shake it all together until the powdered sugar or cornstarch has coated the marshmallows evenly.

This will stop the marshmallows from sticking together and you should be able to eat them without them causing too much of a sticky mess.

Are Marshmallows Diet-Friendly?

Marshmallows are quite high in sugar, and one or two marshmallows a day might be fine, but any more and you will be consuming a large sugar content

Foods such as marshmallows are also low in nutrition, so other than giving you a sugar boost and satisfying your sweet craving, they aren’t doing any good.

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