What Really Happens When You Microwave Peeps

Spring is in the air — the sun is shining, the flowers are blooming, and the grocery store is full of Peeps! Those little marshmallow-based confections are one of the sure signs that spring has arrived. In the 70 years since they were invented by Bob Born, they’ve secured a spot as one of the most beloved treats for Easter (not to mention Halloween, Christmas, and Valentine’s Day, for which there are completely new broods of Peeps to love). 

While Peeps are delightfully sweet and squishy right out of the package, if you’ve spent time on social media lately you may have seen folks doing something a little different with these cute Easter sweets: microwaving Peeps!

Microwaving Peeps is super quick and easy to do. Place a single Peep on a microwave-safe plate, and microwave for about 20 to 25 seconds. In mere seconds, you’ll see the small chickadee puff up like a balloon. Because there are so many varieties of Peeps available, it’s important to note that the results should be similar with any flavor, but different ingredients may affect the final product slightly. The standard ingredients in Peeps are sugar, corn syrup, gelatin, and less than 0.5% of Yellow #5, Potassium Sorbate, Natural Flavors, and Carnuba Wax. But what the ingredient list doesn’t include is something that ends up making all the difference: air! 

Within each Peep, the mixture of sugar, corn syrup, and gelatin creates air bubbles, which help the sweets keep their characteristic shape. Microwaves heat from the inside out, so when you microwave a Peep, the water molecules in the corn syrup heat rapidly, creating steam, which forces the air bubbles to expand, causing your Peep to swell to four times its original size — but for just a moment — before deflating to a goopy mess on your plate (you did remember to use a plate, didn’t you?).

As soon as you take the Peeps out of the microwave, you’ll see all the effects of the experiment. First, you’ll note a slightly nutty, burnt sugar smell — a result of the sugars breaking down within. You’ll also see the Peeps’ stretchy, gooey consistency, like a cheese pull but for marshmallows. In terms of flavor, a microwaved Peep is very similar to its uncooked counterparts, but because texture is so important to the Peeps experience, these hit way different. They become chewy or even crunchy depending on how much time they’ve spent in the microwave. (Because this relies on the specific ingredient combination present in Peeps, this experiment won’t work with vegan varieties.)

Once you’ve microwaved a Peep, there’s not much you can do with it (although you can use them to make edible slime). A better alternative is to bake or fire-roast your Peeps, like toasting marshmallows for s’mores. One year, my stepmother used Peeps to top her sweet potato casserole instead of the traditional marshmallows. It worked beautifully, and, for the most part, you can substitute Peeps for regular marshmallows in many recipes. Here are some of our favorites.