Peeps and Temperature
Last week was Valentine’s Day, so you may have some leftover candy to use up! One classic Valentine’s Day Candy you might have is marshmallow Peeps (you might see these more at Easter, but the heart ones have become popular!). How exactly are Peeps (or any marshmallows) made?
List the ingredients that you think might be in marshmallows.
The answer: Sugar, gelatin, water, and AIR. Marshmallows are mostly made of sugar that has been whipped to include lots of tiny air bubbles. Marshmallows start out as a liquid sugar mixture, and then gas is incorporated to form an airy foam. In the past, marshmallows used to contain the root of the marsh-mallow plant for medicinal reasons, but you won’t find any marsh-mallow root in most marshmallows you see today. Now, we mostly enjoy marshmallows as a fun, sweet treat.
Heat a Peep!
What happens when you heat something? Molecules begin to move faster as they are heated, which causes them to expand. When something is cooled, the molecules begin to slow down and become more uniform.
When you heat a marshmallow, those air pockets that are already part of the foam expand, which causes your marshmallow to expand! As it cools back down, the marshmallow shrinks in size. If the marshmallow expands too much those air pockets burst, and the marshmallow cannot re-expand.
Here is some more information about what happens when you heat a marshmallow:
Let’s test this out!
1. Tear apart a row of Peeps (you’ll need 3 Peeps).
4. Leave one Peep on a plate at room temperature. This is your control Peep. You will compare your results from the freezer Peep and microwaved Peep to see how size has changed.
5. Make your predictions! Will the freezer Peep change in size? Why? Will a heated Peep change in size? Why? Think about what you read.
6. After your 10 minutes is up, remove the freezer Peep. Below, the one on the left is the freezer Peep. The one on the right is the control Peep. The freezer Peep did not shrink noticeably.
8. Record your results.
Findings: We found that the freezer Peep stayed about the same size, but felt much firmer; the air molecules probably condensed and the cold made the sugar molecules lose their elasticity, making the marshmallow denser. The heated Peep grew immensely in size! The measurement across was over 7 cm, but it also expanded in height and length. It grew to its largest size after about 40 seconds. Once the Peep cooled, it was small, dry and crunchy. If you break it open, you might even see that it's a little burnt inside.
Notice that Peeps are made of sugar, corn syrup, and gelatin. All ingredients that we’ve used to make slime in the past!
YOU WILL NEED:
* Peeps (at least 5)
* Corn starch
* Powdered sugar
* Microwave safe bowl
1. Tear apart at least five Peeps and put them in a microwave safe bowl.
3. Heat your Peeps for 30 seconds. Watch what happens as they heat up!
8. Add a final tablespoon of starch and your slime should be ready to go!
11. We noticed it got a lot more goopy and sticky. Why do you think this is? Remember, your marshmallows started out with a lot of air bubbles… what do you think is happening as you continue to heat and play with the marshmallow slime? Add cornstarch again to get more of a dough-like feel.