We are reader-supported. When you buy through links on our site, we may earn a commission. Learn more about our review process.

Nerdy Science in the Kitchen

How to Keep Marshmallows Fresh



pastel colored marshmallows piled in bowl
Marshmallows are a favorite for people of all ages. Learn how to keep them fresh here.

They’re sweet and sugary and airy and yummy. They’re delicious in hot chocolate, on sweet potato casseroles, or just fresh from the bag.

However, those who love to keep a bag of marshmallows in their pantry know the struggle to keep them fresh once the bag has been opened.

Sealing it or tying it correctly does not always work, as marshmallows seem to stick together, resulting in a gooey mess that ends up thrown in the trash.

The real question is: how do you keep marshmallows fresh after the bag has been opened? Is there any way at all? Keep reading to find out how to keep those marshmallows fresh for your next s’mores campfire night.

Why Do Marshmallows Get Sticky?

A marshmallow is a combination of water and sugar that’s whipped to create air pockets. It is these air pockets that maintain the marshmallow’s shape and texture.

If the air pockets are exposed to moisture, the marshmallow will collapse and also become that sticky, gooey mass that all of us have discovered at one time when reaching for an opened bag of marshmallows.

What you need to do is prevent moisture to avoid a big bag of sticky, marshmallow-y messiness. But, since marshmallows are definitely not something everyone uses every day, keeping them in their original fresh and non-sticky form can be difficult. We’ll share with you here some easy tips on how to store marshmallows to keep them fresh and ready for the next time you need them.

How to Store Marshmallows to Keep Them Fresh

Storing Marshmallows in the Refrigerator

Marshmallows remain freshest when kept in a place that is cool and dry. What best fits that description? That’s right–your kitchen refrigerator!

To store your marshmallows in the refrigerator, follow these easy steps:

1. Place the marshmallows in a sealable,, air-tight container.

2. Sprinkle cornstarch or a dash of powdered sugar on the marshmallows. The powder helps to absorb any moisture in your fridge.

3. Shake the container so that the marshmallows are coated with the sugar or cornstarch. This ensures they will not stick together.

4. Store the marshmallows in the airtight container in the refrigerator until it’s time to use them.

Marshmallows stored this way will remain fresh for 2 to 3 months inside the fridge.

marshmallow on stick dipped in white bowl of melted chocolate
Keep your marshmallows fresh and ready for the next time you need a sweet treat.

Storing Marshmallows in the Freezer

So, you’ve opened up a bag of marshmallows to throw a couple into your cocoa. If you are not going to use or eat the remaining marshmallows anytime soon, it is best to keep them in the freezer to keep them fresh until you’ll need them again.

To store marshmallows inside the freezer, follow these easy steps:

1. Place your marshmallows inside a container with a tight-fitting lid. If you don’t have any, you can use a freezer-safe or Ziploc bag.

2. Place only a few marshmallows in each container to keep from squishing the marshmallows together.

3. Seal the container or bag properly and place it in your freezer. The marshmallows will stay fresh for 3 to 4 months once stored correctly in your kitchen freezer or deep-freeze in the garage. Thaw them at room temperature when you’re ready to eat or use them.

TIP: If you’re need to slice marshmallows before adding them to a recipe, slice them while they’re still frozen. They slice more easily that way.

Storing Marshmallows at Room Temperature

Maybe room in your refrigerator or freezer is at a minimum. Don’t worry!

You can store marshmallows at room temperature using the bread method.

To do so, follow these easy steps:

1. Once you have opened the bag of marshmallows, place a single piece of white bread inside the bag with the sweets.

2. Twist the bag’s opening and use a rubber band or plastic clips to seal the opening securely.

3. Store the marshmallow bag at room temperature, keeping the bag away from heat or light exposure. (It’s best to keep them in a cabinet for this purpose.)

4. The next time you need some marshmallows, replace the old bread with a new slice and seal the bag again using the clips or rubber band.

The bread method works well in keeping marshmallows fresh if you live in a cool environment. If you live in a warmer climate, you really do want to store them in the fridge or freezer.


Keeping marshmallows fresh once the bag is opened is actually simple.

Store marshmallows in airtight containers in the refrigerator or freezer, or at room temperature using the bread method above.

All these techniques prevent moisture from getting to the marshmallows, keeping them from sticking together.

Frequently Asked Questions:

How long will marshmallows stay fresh?

Marshmallows stay fresh for around 3 to 4 months if you store them correctly in the fridge, freezer, or at room temperature using the bread method above.

What causes marshmallows to stick together?

Moisture causes marshmallows to stick together. When it enters the marshmallow bag or container, the air pockets, which maintains the marshmallow shape, collapse, causing the gooey, sticky mess we all hate.

Do marshmallows go bad?

Yes, actually. You can tell if your marshmallows are bad when you spot discoloration or note a change in their taste. This usually happens if the bag has been kept too long in a humid or moist spot.

Additional Resources:

Image Credits from Pexels: Photo by Votsis Panagiotis from Pexels; Photo by Nerfee Mirandilla from Pexels,

Kitchen Professor author
About the Author: Rhonda Richardson, Editor

Rhonda grew up with parents who gardened, hunted, fished, canned, and preserved food. Her mother was a professional cook and Rhonda credits her teaching everything from how to make homemade biscuits and gravy to what kind of meals to serve for different occasions. In the kitchen, Rhonda uses a mix of old-fashioned country cooking and up-to-date fads in the kitchen, often experimenting with replacing higher-calorie or fat ingredients with healthier options that still retain the delicious flavors of the originals.

Leave a Comment