How do you keep marshmallows fresh after you’ve opened the bag?
You know what happens: after you tear open a sealed bag and measure out the marshmallows you need in a cookie recipe, you put a twist tie on the bag and set the bag on your pantry shelf …
… until the next time you need marshmallows in a cookie recipe. You pull out the bag and find you have a gooey mess. The marshmallows left in the bag stick together.
Marshmallows are made from a mixture of sugar (or corn syrup), gelatin, and water. The ingredients are whipped together into a spongy texture. Put simply, marshmallows are sugar and water wrapped around bubbles. Air pockets help marshmallows keep their shape.
So just a bit of moisture pumped into those air pockets makes them collapse.
That’s what happens once you open a bag of marshmallows. Moisture from the air slips into the bag, and then into the marshmallows, filling up the air pockets.
Which leaves you with glop.
Bottom line: to keep marshmallows fresh and not sticky, you need to keep moisture out of the marshmallow bag once you open it.
There are at least 3 ways you can do that. Try these tips to keep moisture out of your open bag of marshmallows so they stay fresh and ready to use in your next cookie recipe.
To keep marshmallows fresh, set the opened marshmallows in a container with a tight-fitting lid or in a freezer-safe, Ziploc plastic bag. Avoid packing too many marshmallows into the container or bag because it will squish them together. Seal the container or bag securely. Then store the bag in the freezer.
To use the marshmallows, remove the bag from the freezer and set them on the counter for 10-15 minutes at room temperature before using them so they can defrost. If the marshmallows stick together, sprinkle a dash of powdered sugar or cornstarch in the bag and shake to coat them. The marshmallows should break apart.
If you plan to slice marshmallows, you don’t need to let them thaw. Simply remove them from the freezer and get to work. They slice easily when frozen.
Marshmallows will keep in the freezer for up to 3-4 months.
The principle is the same for storing an opened bag of marshmallows in the refrigerator as when storing it the freezer: the marshmallows will be in a cool, dry place. To offset the slightly higher humidity in refrigerators over freezers, you need to add one step.
Remove the marshmallows from the original package and place them in an airtight container or plastic Ziploc bag. At this point, sprinkle a dash of powdered sugar or cornstarch over the marshmallows. The extra powder will collect the bit of extra moisture from the refrigerator’s air. Seal the container or zipped bag opening. Then shake the container to coat the marshmallows and prevent them from sticking together.
Remove marshmallows from the refrigerator when you’re ready to use them.
You can store the marshmallows in a dark corner of the refrigerator for 2-3 months.
Maybe your refrigerator and freezer are full … or maybe you don’t have one. In that case, place a piece of white bread in the opened marshmallow bag. Twist the bag’s opening and seal it with a rubber band or twist tie. Set the bag away from direct light and in a cool, dry place.
The bread pulls moisture out of the air and away from the marshmallows to keep them fresher for longer.
Get more tips about baking cookies on our Baking Tips Pinterest board.
More Cookie Baking Tips from The Cookie Elf