Easter Science with Peeps!

Do your kids end up with a huge influx of candy after Easter? We certainly do, and if the kids haven’t eaten all of it, it’s always fun to think of other things we can do with it besides eating it! With that in mind, we’re taking a look at one of the most common Easter candies, and some science we can do on our peeptastic Easter adventures! Here, you’ll find three experiments you can do with marshmallow peeps, a detailed explanation of the science behind the experiment, and a fun and creative way you can bring some art, design, and creativity to your Easter peep fun!


Materials Needed:

3 peeps of the same color and shape
3 glasses or beakers
1/2 cup vinegar
1/2 cup water
1/2 cup isopropyl alcohol
Time: This experiment will be observed over a period of 48 hours


Pour your solutions into each of the glasses or beakers. The water will act as the control, which you will compare the other solutions against.

Then, place one peep into each of the glasses, setting it in the center of your glass, away from the sides.

Have your kids make detailed observations of the peeps and what they look like in their current state. You can have your kids make a data table and write descriptions of what they see, or they can draw pictures of what the peeps look like in each of the jars!

Place the peeps in a cool dry place, away from any curious hands. Each day, you can bring the peeps down so the kids can observe any changes in the peeps! They can include these changes in their data tables or drawings.

Finally, after 48 hours is up, take the peeps down and examine them! Look for any changes in color, texture, or size. Have the peeps dissolved at all? What changes occured while the peeps were in their solutions?

What’s Happening?

Peeps are made of fluffed up sugar, water, and proteins in the form of gelatin. This strong gelatinous substance is fairly insoluble when it comes to water and other liquids! The sugar will dissolve, and the colored candy coating will dissolve as well, allowing the colors to seep back into the peeps. However, you won’t find any dissolving action in these marshmallow critters.

Seriously, the folks at Peep Research (yes this is a thing and it’s awesome!) tested the solubility of peeps in various solutions and found that only the incredibly caustic and toxic chemical Phenol could dissolve the peeps! It withstood all others, including sulfuric acid!

We didn’t have these chemicals on hand, so we used isopropyl alcohol, water, and vinegar. We also tested the effects of acetone on peeps during our 12 Days of Science project!

Giant Inflatable Marshmallow Peeps!

Materials Needed:

Large Plate
2 peeps of the same color and shape


Place one of your peeps on your plate. Then place it in microwave and cook it for about 30 seconds. Watch as your peep grows to more than 5 times its size as it inflates into a giant sugary ball of marshmallow fluff!

Take your plate out of the microwave, and place your first peep next to the microwaved one to compare its size. You will notice the microwaved peep will quickly deflate as it begins to cool. So have your peeps ready to compare as soon as it gets out of the microwave!

What’s Happening?

Marshmallow Peeps are made primarily of sugar, water, and gelatin, and have been puffed up with air. When you added heat to the mixture, this excited all of the molecules in the marshmallows! Suddenly the molecules, that were already quite far apart to begin with (in the puffed up air) are dancing and bouncing and spreading even further apart! The water began heating up and turning into steam, which softened the gelatinous texture of the marshmallow. This softer boundary allowed for quick expansion as the rest of the molecules started bouncing around like crazy!

You may also see some discoloration on the inside of your snowman. If you see brown or black colors, this means that the sugar has heated up so much that it’s melted! It has caramelized and has turned into hard, crystalline structure!

Roasted Marshmallow Peeps!

Materials Needed:

One peep
Long barbecue lighter, or a campfire!
Dowel, skewer, or roasted marshmallow spear


Push your dowel, skewer, or spear into the center of your marshmallow peep. Make sure it’s held firmly in place so it doesn’t fall off as you’re roasting it!

Carefully light your lighter, and hold it under your peep! You can either roast it traditionally, so it’s lightly browned and toasted, or you can light that peep on fire and get a crispy outer shell that you can pull off!

Once your peep is roasted to perfection, then it’s time to relish in the delights of physics and peeps!

What’s Happening?

As you bring the fire to your peep, it begins to heat up the molecules inside of it. As they start bouncing around, they may expand, resulting in a “puffing up” of your marshmallow peep. The discoloration of your peep occurs when the sugared coating of the marshmallow candy gets caramelized and turns brown! If it turns black (like ours did), that means the sugar has been caramlized until it has burnt. Then you can peel off the rough outer shell and eat the soft and gooey sugary marshmallow underneath!

Finally, if you’re like us, and end up amassing a collection of dozens of peeps for your science and candy adventures, here’s one more way you can have a blast with peeps and explore your creative side along the way!

Hamilton: The Marshmallow Musical!

My daughter is obsessed with the musical Hamilton, so we created our own mock stage with the characters of Hamilton, peep style! We used fabric, glitter, craft foam, sequins, and a myriad of other supplies to deck out our peeps in their costumed characters and had a blast setting different stage designs! You can adapt this to characters out of a favorite book, movie, band, or musical!

Happy Exploring!

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