- [Rob Voiceover] Are you feeling curious?

- [Kids] Yeah.

- Today on "Curious Crew."

- Oh, whoa.

- [Rob Voiceover] We've got s'more fun.

- They're so sticky.

- [Rob Voiceover] As we explore marshmallow chemistry.

Amazing!

Unless the crew eats them all first.

(man laughing) - [Female Voiceover] Support for "Curious Crew" is provided by MSU Federal Credit Union.

From sweet peas to teens, MSU FCU offers you accounts that grow with children.

With financial education, gaming apps, and events, MSU FCU provides the tools and resources to make learning about finances fun and interactive.

Also by, the Consumers Energy Foundation, dedicated to ensuring Michigan residents have access to world-class educational resources.

More information is available at consumersenergy.com/foundation.

Consumers Energy Foundation, supporting education and building sustainable communities in Michigan's hometowns.

And by viewers like you!

Thank you!

(bright rock music) - Hi.

I'm Rob Stevenson and this is... - [Kids] "Curious Crew!"

- Welcome to the show, everybody.

We always like to start every episode with a couple of discrepant events because discrepant events stimulate... - [Kids] Curiosity.

- That's exactly right.

And I've got some fun ones for you today.

First, I wanna direct your attention right down here to this beautiful marshmallow swirl.

Now, I've placed this marshmallow swirl in what's called a bell jar.

You'll notice there's a base and there's even a little rubber strip that goes around here, which is great for making the airtight seal.

Because once I put this bell on the top, I can pump air out of the chamber using an air pump I have down on the floor, and I can control it with my foot.

Adia, what do you think is gonna happen to this marshmallow swirl if I pump the air out of the chamber?

- I think it's gonna get bigger.

- So we're gonna try this, and in fact, I'll turn off the pump at a certain moment and I'm gonna squeeze this little tube in the back with these channel locks and just look at it for just a moment.

Here we go.

(suspenseful music) (Rob laughing) Okay.

I've pinched off the tube in the back.

Now, watch closely when we let some air go back in.

(Rob laughing) That's hilarious.

Okay.

So now, I wanna direct your attention, I've got a couple of marshmallows right over here and we're gonna place these in the microwave for 10 seconds because I would like to do a little comparison to see which one of these will stretch the most.

Now, you might notice I've taken a little bit of precaution by putting some gloves on because marshmallows get sticky and I don't really want marshmallows all over my fingers.

So, here we go.

We've got warmed up marshmallows, and Kah'reice, you tell me which one stretches the best, okay?

Let's look at this one here.

Oh, whoa.

(Rob laughing) Hey, Kah'reice, which one stretches the best?

- I think the second one stretches the best.

- I think you're totally right.

That is really stretchy.

This is like a surgical trick where you put the glove right inside of itself and you can keep your hands nice and clean.

Now, I'm gonna ask three of you to do a little bit of scientific modeling to see if you can explain these discrepant events by the end.

Who wants to do a little modeling moment today?

Who would like to try that?

Callan, Janellyn, and Nash.

You three are gonna do that.

Now, does anybody have a guess what we're gonna be investigating today?

I bet you all have a guess what we're gonna be investigating.

What are we gonna investigate today, Ian?

- Are we talking about marshmallows?

- We are talking about marshmallows.

Marshmallow chemistry, in fact, and I have the perfect tie for this episode.

If you look closely at this tie, it's covered with these dragons that are actually roasting their own marshmallows.

Delightful.

You're gonna wanna stick around 'cause we have s'more to share.

(upbeat hip hop music) - I was thinking about the inflatable marshmallow.

It kind of reminded me of blowing up a balloon.

- I can see that.

Although it's a good thing it didn't pop.

- Yeah, that would've been a mess.

But why do you think Dr.

Rob warmed up the other marshmallows?

Do you think the results would've been the same even if he didn't warm them up?

- Oh, that's a good question.

(upbeat electronic music) - [Rob Voiceover] Did you know that the original marshmallow was made from the root of a marshmallow plant?

It's true.

Ancient Egyptians used the root as medicine for sore throats, but at that time, it wasn't very tasty.

They later took its sap and combined it with honey and nuts.

It wasn't until the 1850s that French candy makers cooked the root sap with egg whites, corn syrup, and water, making a much sweeter candy.

The mixture was poured into corn starch molds to cool.

By the 1950s, food engineers changed the ingredients once again, making one of the recipes still used today.

S'more, please.

(mysterious electronic music) Weren't those discrepant events fun, you guys?

- Yeah.

- Yeah.

- I think so, too.

Now of course, if we wanna understand marshmallow chemistry, we have to think about the ingredients that are in marshmallows.

And I've got an interesting investigation to get us thinking about this.

It's gonna start with a cup of water and some mini marshmallows.

Now, I know you guys have those standing by.

Do me a favor.

Grab a little mini marshmallow or two, and Adia, predict for me what's gonna happen if we drop them in the water.

- I think if we drop them in the water, they're going to float.

- Why might they float?

- Because they're light and full of a lot of air.

- Okay.

Let's drop 'em in.

Yeah, you're totally correct.

These are going to float great.

Ian, what could we do to get one to sink?

- What if we crush it up?

(Rob giggling) - Okay, I'm gonna try it.

You guys try it.

I'm gonna get my fingers a little wet here.

Now, if we squeeze it and squeeze it and maybe even roll it around in our hands a little bit, we can actually try to crush, oh, you're doing a great job there, crush and collapse some of those air pockets that are inside.

I wonder if we can do it enough where we can change the density of the marshmallow and get it to sink.

I'm gonna try mine.

Nope.

It still floats.

(Rob laughing) There's a lot of air in that marshmallow.

But what else is in a marshmallow?

Take a look at these ingredients.

We've got sugar, corn syrup, gelatin, and water.

That's pretty much all that's in a marshmallow.

We combine that, we whip it together with a lot of air, and we've got a marshmallow.

Now, I know that you realize that marshmallows are kind of sweet.

So how many grams of sugar do you think there is in a single marshmallow?

What do you guess?

How many grams, Ian?

- 10?

- That would be a lot.

Fortunately, it's less than that.

It's actually four grams of sugar, which is still a lot.

It makes it sweet, right?

Now, of course, the sugar combined with the syrup combined with the water and the gelatin and mostly... - Air.

- Air.

- Makes a wonderfully buoyant marshmallow, which is especially fun in a cup of hot cocoa.

- [Rob Voiceover] Although it takes about an hour to make a marshmallow, food engineers have selected ingredients that determine a marshmallow's interesting properties.

Most marshmallows are made from sugar, corn syrup, gelatin, water, and air.

Gelatin is animal protein molecules from collagen, but when they combine with warm water, the molecular helices unravel and lengthen.

As it cools, some of the strands wind back together in threes while others remain flexible.

This combination of firm helices with bendy strands makes traditional marshmallows very elastic and squishy.

What fun?

(mysterious electronic music) - So you know if we're talking marshmallow chemistry, we have to talk about s'mores.

Do you guys like s'mores more?

- Yeah.

- Yeah.

- Oh yeah.

And of course, I'm curious.

Do you like them slow roasted over a fire or in a microwave?

How about you, Janellyn?

- I definitely like them over a fire.

- Okay.

How about you, Kah'reice?

(Rob laughing) - I like them over a fire.

- Me too.

Now, in fact, I asked you to make some in a microwave and I'm curious, when you did that, Kah'reice, what did you notice when you watched the marshmallow in the microwave?

- I noticed that it expanded.

- Okay.

I wanna see that for myself.

So I've got a s'more that's ready.

I'm gonna put this in the microwave here and just heat it up for about 10 seconds or so.

And we'll take a look at what happens.

(clock ticking) (upbeat electronic music) (microwave beeping) - Whoa.

- And of course, when we pull it out, it's a little swollen.

And of course, I think we need to put some hats on our marshmallows.

What do you guys think?

- I know you have some ready.

- Yeah.

- Let's put 'em on there.

You guys put 'em on yours, I'll put 'em on mine.

I'm wondering, though, why does it swell up in the microwave, Janellyn, why do you think?

- I think it might have something to do with like the heat from the microwave causing like gas particles inside to expand, maybe?

- Okay.

So this is what's really interesting.

If we can add heat to gas particles, they move faster, and if they move faster, they bump into things more frequently and harder.

And we know there's a lot of air trapped inside a marshmallow.

So if we can add enough heat, those particles are bouncing around and it starts to swell up, and swell up, and swell up.

This was first discovered by a French scientist named Jacques Charles back in the 1780s.

He was not playing with marshmallows when he discovered this, but what he realized is if we increased temperature, we increase pressure.

Now of course, when the marshmallow cools, it can shrink down again.

And I'm almost ready to eat this, but I wanna share one other thing with you.

Have you guys ever heard of marshmallow jousting before?

(Rob laughing) - No, I haven't.

- This is so silly.

Okay.

So let me show you this other plate that I've got right here.

It almost looks like these two little knights that could be defending the castle from the marshmallow dragons on my tie.

Now, if you ever wanna do this, it works best with Peeps because Peeps have a really wide base.

But the idea is this.

You poke a toothpick into two opposing marshmallows with the toothpicks facing each other.

Then you put it in the microwave, watch them swell up, and see which one gets poked first.

It's a pretty silly activity, but the cleanup is delicious.

- [Rob Voiceover] It's been estimated that 90 million pounds of marshmallows are purchased and enjoyed each year, but during the summer months, half of the marshmallows sold get cooked over an open fire and eaten as a s'more, short for some more.

That recipe even dates to the 1920s where it was described as a graham cracker sandwich.

Now the current record for the largest s'more was in December 2019 at Camp Meade in Vermont at the annual "Winter S'morestice" event in which 1,000 people got to enjoy the five by eight foot 343 pound treat.

Talk about some more.

(bright jazz music) - What are we gonna talk about today?

(upbeat hip hop music) We're actually gonna be talking about electric circuits.

- In the electrical circuits episode, it was explaining how humans can be circuits, too.

- We have my cute little ball over there!

- We had this little smiley thing and there were two sides of it where we could put our fingers on it.

And we did a whole group chain of everyone that was on that episode that time.

It lit up and it was so cute.

I loved it.

- This is a human circuit at its finest.

(upbeat electronic music) - [Announcer] S.T.E.M challenge!

- So have you had fun exploring marshmallow chemistry so far, you guys?

- [Kids] Yeah.

- That's awesome.

Now, you know the S.T.E.M challenge has to involve marshmallows, and in fact, I've given you an abundance of different kinds of marshmallows for this S.T.E.M challenge, but we're gonna be tapping your artistry skills today.

In addition to marshmallows, you've got some wooden sticks, toothpicks, wooden skewers, all sorts of paraphernalia because you are going to design and build an animal out of marshmallows.

In other words, a marshmallow mammal.

Are you ready to start your build, you guys?

- [Kids] Yeah.

- [Rob] Let's do it.

- The materials we are using are marshmallows, some skewers, toothpicks, tape if you need it.

- I decided to make an elephant, and to do this, I realized I had to make legs first.

So I took a couple of the tiny marshmallows to make its legs.

Then I took some of the bigger marshmallows to make its body.

So now, I think I'm gonna use some colorful marshmallows for its ears.

- I decided to make a giraffe because they have long necks and I thought if I could perfect that, it'd be really cool.

- The biggest challenge for me was sticking the marshmallows on the skier because it was hard to push them and then they were really sticky and they were sticking to my fingers.

They're so sticky.

- Ooh.

I have to worry about balance because if the neck is too long, it might tip over.

I already knew it was gonna be a big challenge with getting it to stand up.

Now for the test.

Will it stand?

Kind of.

- So I finished my elephant, but I think something's missing.

Oh, right.

I need to add a nose.

Finally, I added its eyes on as well as a paper nose.

- That looks really good.

Another big challenge was not eating the marshmallows because they just look really yummy.

- Yeah.

I kind of wanna eat them.

- I'm definitely not planning on eating my mammal, but I'll definitely eat the leftovers.

- [Kah'reice] I think that I'm done.

- [Adia] Price is kind of sad.

- [Ian] And tah-dah.

My marshmallow animal is finished.

- So it looks like you're all just about finished with your build.

Adia, let's start with you.

What did you build?

- I built a wiener dog.

- What are those marshmallows?

- I have regular marshmallows, and mini vegan marshmallows, and some pumpkin spice marshmallow.

- Oh, pumpkin spice for the feet.

Okay.

Ian, what did you make?

- I made a tiny little elephant.

And the thing that I really like about it is I used colored marshmallows for its ears.

- You can totally see that.

That's really funny.

So Kah'reice, what did you make?

- I made a giraffe.

- And what marshmallows did you use there?

- I used the pumpkin spice marshmallows, the mini marshmallows, and the regular.

- As you can see, marshmallow structures are kind of fun to make, but making marshmallow mammals, let's just face it, they're adorable.

Try making your own marshmallow mammal.

See what you can create.

- [Rob Voiceover] The crew was really creative with some of the marshmallow mammals they made.

The properties of the marshmallows really compliment the possibilities with this S.T.E.M challenge, too.

Not only do the ingredients allow the wood sticks to penetrate easily, but the sticky nature also holds the wood in place.

When marshmallows are left out in the air, some of the moisture evaporates out, making the outside slightly firmer, which will help stabilize the mammals, so long as it doesn't get too warm.

Try making your own marshmallow mammal, but be sure to save some to eat as well.

(mysterious electronic music) When you're cooking marshmallows, do you like them better out of the microwave or over an open fire?

Callan, how about you?

- Over an open fire.

- Over an open fire.

And Nash, how about you?

- I honestly just prefer them plain.

- Nice.

Okay.

Now most people will say open fire and I'm gonna tell you why.

There actually a chemical explanation for that.

Have you ever noticed when you take your time, you put it near the fire, it starts to turn brown?

Kind of like these marshmallows I have down here.

So I've browned these marshmallows, and you do have to be patient, but this browning effect is called caramelizing.

And it actually does something and changes the flavor of the marshmallow.

In fact, the sugar that is inside the marshmallow, the molecules start to break down.

There's a chemical reaction and it produces new flavors, like butter, nutty flavors, even fruity flavors, and they react with the gelatin in traditional marshmallows and add even more flavors.

So if you want a flavorful marshmallow over a fire, slowly roasted is perfection.

So this is the optimal method.

Now, I mentioned gelatin marshmallows, but those are not the only kinds, right?

There are plant-based marshmallows and we're gonna do a little comparison between them.

You each have one gelatin marshmallow and one plant-based marshmallow.

And the first question I have for you, Nash, when you look at them, what do you see as a visual difference, if any?

- There's not much difference.

- I have a question for you, Callan.

Can you give them each a squeeze and tell me which is more squeezable?

- The gelatin one.

- The gelatin one is a little more squeezable, and in fact, we can even see that when I press on them.

So you might be thinking, okay, let's think about the chemistry.

Why is that so?

Well, it has to do with the molecules in gelatin-based marshmallows.

When they heat up, they unravel, they stretch out, and when they dry up and cool off again, they end up making this interesting shape that makes a really flexible matrix.

Now, plant-based marshmallows don't use gelatin, so they need a different structure source.

Here, we used protein soy and we used carrageenan from seaweed, and together, we have a different kind of marshmallow.

Let's test something else.

I'm gonna ask you guys to do a stretch test, okay?

Callan, I want you to stretch the gelatin-based, and Nash, you stretch the plant-based and we'll see what happens.

- Oh yeah..

It's stretching, stretching, stretching.

Okay.

Nash, yours broke a little bit.

I'm not too surprised by that.

We would expect that.

Remember, it's not quite as stretchable, but now that yours is broken, Nash, look inside.

What does it look like in there?

- It looks like a sponge kind of.

- Looks like a sponge.

And that's the difference between the two kinds of marshmallows.

But of course, if we're doing a test like this, there's one test that's more important than anything else, and that's taste.

Now, most of us have had gelatin-based marshmallows.

So Callan, have you ever tried a plant-based marshmallow before?

- I have not.

- I think it's time for you to taste it.

Let us know what you think.

- That's really good.

- It is really good.

So gelatin-based marshmallows have been around for a really long time, but with plant-based marshmallows, it gives us another delicious option.

- [Rob Voiceover] We have seen how the molecular bonds in marshmallows can trap the air.

That trapped air is what makes the marshmallows so bouncy, yet still maintain a stable shape.

But what if there were hardly any air in the mixture?

Those same ingredients could end up with very different material properties.

By adding a bit more gelatin to the recipe, you could end up with gummy bears.

The ingredients are the same, but the extra gelatin in the gummies makes the candy firmer while the whipped air makes the marshmallows squishier.

Chemistry sure is sweet.

(bright violin music) - Are you curious about careers in science?

Hi, I'm Genesis, and today, I'm here with Nikki Thompson-Frazier.

Nikki, can you tell me where you are and what you do?

- [Nikki] I own "Sweet Encounter" bakery located here in Lansing, Michigan.

And I specialize in gluten-free and allergy-friendly products.

- How is S.T.E.M incorporated into baking and what different ingredients do you use when you're baking gluten-free treats?

- Baking truly is a science.

I tell people that all the time.

From the temperature that you use to bake your items, also, we have to measure those ingredients.

With gluten-free, gluten is the thing that kind of binds your bake goods together.

So, I can't use like regular flour.

I use a flower blend that I create.

So you kind of have to put a lot of different things in there to kind of substitute for the wheat flour that you would just typically buy at the grocery store.

- Learning about S.T.E.M with Nikki Thompson-Frazier was a piece of cake!

Explore your possibilities!

(bright violin music) And now, back to "Curious Crew."

(upbeat hip hop music) - So we know the main ingredient in marshmallows is air.

The air must have expanded, making the marshmallow inflate.

- That's probably right.

And it's like how the marshmallows got heated up in the microwave and they swelled up because of all the kinetic energy in the air particles.

- Yeah!

And you know, I think with the other marshmallows, one of them was gelatin-based while the other one was plant-based because we know that different ingredients comes from material properties in the marshmallows, right?

So that could explain why one of them stretched more than the other.

- So have you had fun investigating marshmallow chemistry today, you guys?

- [Kids] Yeah!

- That's excellent.

And I'm sure you've been thinking about these discrepant events from the beginning of the show and some of you have been doing some good thinking about this.

What have we figured out about the inflatable marshmallow, Janellyn?

- Well, we know that there's a lot of air inside marshmallows.

So as air leaves the bell, there are fewer air particles hitting the outside of the marshmallow, but that means the inside of the marshmallow gets to push those air particles outward, which makes it expand and get bigger and bigger.

- Exactly!

And of course, because of the chemistry of marshmallows, we've got sugars and gelatin and that's not nearly strong enough to be able to keep those air particles inside.

Now, of course, I'm sure you wanna see this one more time, so let's do it one more time.

I won't close it off this time.

We'll inflate it.

Look at that grow.

Look at that grow!

All the while we've got particles that are going out of this chamber and the particles that are inside the marshmallow are pushing, and pushing, and pushing.

And the entire thing will stretch.

Now, of course, I'm gonna stop.

Let's see what happens.

Which is just so fun to watch.

This is a great example of Boyle's law.

Robert Boyle was a scientist who lived back in the 1600s and he realized there's an inverse relationship between pressure and volume.

So what does that actually mean?

Well, as Janellyn was describing, when there's a lot of pressure inside with all those air particles, that marshmallow's gonna stay small, but if we can get the pressure out, those particles in the marshmallow start to take up more space and the whole marshmallow swells up.

Amazing!

So what about our stretchy comparison, Callan?

What did we figure out there?

- We think that the marshmallow that stretched more was gelatin-based and the marshmallow that stretched less was plant-based.

- We know that plant-based marshmallows use different ingredients, like seaweed and soy.

And they aren't as elastic as normal marshmallows.

- Either way, the marshmallows taste great, right you guys?

- [Kids] Yeah!

- That's because marshmallow chemistry is really sweet.

So remember, my friends... - [Kids] Stay curious!

- And keep experimenting.

- [Rob Voiceover] Get your curiosity guide and see more programs at wkar.org.

- [FeRob Voiceover] Support for "Curious Crew" is provided by MSU Federal Credit Union.

From sweet peas to teens, MSU FCU offers you accounts that grow with children.

With financial education, gaming apps, and events, MSU FCU provides the tools and resources to make learning about finances fun and interactive.

Also by, the Consumers Energy Foundation, dedicated to ensuring Michigan residents have access to world-class educational resources.

More information is available at consumersenergy.com/foundation.

Consumers Energy Foundation, supporting education and building sustainable communities in Michigan's hometowns.

And by viewers like you!

Thank you!

- Good job, Emily.

If I have chocolate and marshmallow all over my face, Carol will not be happy.

There it is.

There it is.

(Rob laughing) - You guys gotta get your dance move.

(upbeat jazz music) - Yeah!

And go.

And go.

(Rob laughing) (bright piano music)