Do Marshmallows Go Bad?

So you love marshmallows, and you’ve bought yourself a large bag. After opening the package and getting started on the sweets, you realized it will be quite some time until you finish the pack. That’s when you began to wonder: do marshmallow go bad?

Or maybe you’re only getting started on your marshmallows journey. And you’re wondering how to store them after opening the bag and how long will your stash last until it goes stale.

Either way, in this article we cover precisely that: storage, shelf life, and going bad of marshmallows. If you have any questions or doubts regarding this topic, this piece should help you out. If that sounds interesting, read on.

Colorful marshmallows
Image used under Creative Commons from jamieanne

How to Store Marshmallows

Modern marshmallow is made from a mixture of gelatin, sugar, and water. Although marshmallows have a high water content, these treats are shelf-stable. That means as long as you store them in a cool and dark environment, you’re good to go.

When it comes to temperature, room or slightly below is perfect. So a dark cupboard in the pantry or kitchen is a perfect choice. However, if you live in the tropics, it might make sense to refrigerate these sweet treats, especially if you have a history of marshmallows melting and sticking together.

Marshmallows on the window
(credit: Kelly Sikkema)

Once you open the bag, there are a few things to remember. First of all, you should keep them sealed tightly because they harden when exposed to air. The easiest way to go about that is to put the open package to an airtight container. A tight seal is also important because marshmallows tend to pick up strong odors from their environment.

Last but not least, if you decide to store the leftovers in the fridge, you should also protect these sweets from moisture in the air. Fortunately enough, a good airtight container covers all those needs.


Put the leftover marshmallows in the fridge, where they will retain freshness for a bit longer.

If, despite being stored in an airtight container, your marshmallows tend to get sticky after storing them for some time, try sprinkling them evenly with a tablespoon of cornstarch. That should help out with the stickiness.

Can You Freeze Marshmallows?

As it turns out, marshmallows freeze really well. So even though most sellers don’t really talk about whether or not you can freeze their product, give it a shot. Especially if you don’t plan to consume the rest of your stash anytime soon and don’t want to force it so you don’t waste food.

If the bag is unopened, there’s no additional prep needed. Just chuck the bag into the freezer, and you’re good to go. In the package is opened, transfer the candy either to an airtight container or a freezer bag.

No matter which option you go with, remember to not pack the candy too tightly, both in the container and in the freezer (if it’s in a bag). You don’t want to squish the marshmallows in storage.

When it comes to defrosting, the fridge, as usual, is the best option. If the marshmallows turn out sticky, sprinkle them with some powdered sugar or cornstarch. Give the bag a good shake and the marshmallows should be ready to use.

Toasting a Marshmallow
Image used under Creative Commons from jchapiewsky

How Long Do Marshmallows Last

Marshmallows’ shelf life varies from producer to producer, sometimes it’s 2 months, other times even 4 to 6 months. But pretty much every bag comes with a best-by date on the package. And as long as the package is unopened, the marshmallows should be just fine, even after a few weeks after the date on the package.

Once you open the package, the sooner you consume them, the better. While some producers urge you to finish the bag within 3 days, the candies should taste great and not harden for at least a week or sometimes even two.

As time goes by, they will naturally harden and lose their quality. So even though they might be safe to eat after being opened for a month, they probably won’t taste nearly as good as they used to. If you need to store the sweet for longer than 2 weeks, it’s probably better to freeze them.

Marshmallows (unopened)Best-by + 1 month
Marshmallows (opened)1 – 2 weeks

Please note that the periods above are only estimates.

Marshmallows on fire pit
(credit: Leon Contreras)

How To Tell If Marshmallows Are Bad

A freshly opened bag of marshmallow has a sweet yet mild aroma, pillowy-soft texture, and sugary taste. Discoloration and changes in taste may be a sign that your marshmallows have gone bad. This goes especially for a bag of marshmallows that you’ve left in storage for too long or one you’ve kept in a humid or moist storage spot.

Marshmallows that are improperly packed in storage will clump together and become sticky. The change in texture doesn’t mean that the marshmallows are no longer safe to eat, they just turn goopy due to the melted sugars. However, abnormally chewy texture is a sign that the marshmallows are old or poorly packed in storage.

Last but not least, candies of all types will attract a host of pantry bugs, particularly ants. If you stored a package of marshmallows for too long, inspect the bag of the candy first. Make sure that it’s completely sealed and free from holes caused by insects.