Woo!
It’s getting hot out!
Squeaks and I are craving ice cream, but we don’t have any.
So, we’re going to make ice cream using science!
We know that ice cream is made out of cream and sugar and a flavor.
And we know that it’s frozen, but it’s not rock hard like plain ice.
It’s more like very cold whipped cream!
So, we have cream and sugar.
We also have vanilla that we’ll flavor our ice cream with.
And now we’re going to take these three ingredients and turn them into ice cream!
And you can do this at home, too.
You’ll need your three ingredients: sugar, vanilla, and cream.
Or you can use milk or half and half instead of cream.
You’ll also need a measuring cup, measuring spoons, oven mitts or a towel, a small sealable
plastic bag, a large sealable plastic bag, ice cubes, a timer, and a grownup to help.
The last thing you’ll need is the important one: salt!
First, take your three ingredients and put them into the smaller bag.
We’re using a half cup of cream, a half teaspoon of vanilla, and a tablespoon of sugar.
And then, seal up that bag.
Next, put ice into the big bag.
We’re putting four cups of ice in.
That’ll make the cream cold.
But, here’s the amazing scientific part!
We’re going to add salt to the ice.
We’re adding half a cup of salt.
It’s important to add salt to the ice, because that will make the ice cream freeze much faster.
Here’s why:
If you’ve ever put out salt on your sidewalk or driveway in the winter, you know that salt
can melt snow.
That’s because when there’s lots of salt in water, it needs to be colder than plain
water does to freeze.
Even if it’s cold enough outside for /plain/ water to freeze into snow, it’s probably
not cold enough for /salty/ water to freeze!
So when you add salt, the salty snow melts.
When you add salt to the bag of ice, the same thing happens.
The ice is cold enough to freeze when it’s just plain water.
But it’s not cold enough to freeze when there’s lots of salt!
So the ice cubes in the bag start to melt!
That melting is /really/ important for making your ice cream really cold, really fast.
Because as the ice melts, it draws in heat, making the things around it much colder — including
your ice cream!
So, now that we’ve added salt to our bag of ice cubes, the ice is going to start to
melt and make the cream, sugar, and vanilla in the smaller bag REALLY cold.
While that’s happening, we’re going to make sure the ingredients in the bag become
ice cream!
This is where we need our oven mitts or a towel because this bag is really cold.
Protect your hands and hold onto the bag.
Now we’re going to shake it!
It’s good to have a friend to help you with this part.
Squeaks and I have made butter before, and we shook up the cream until it got hard and
turned into butter.
But before it turned into butter, it was soft and fluffy whipped cream.
Ice cream is harder than whipped cream, but softer than butter, so we’ll have to shake
our cream /longer/ than we would to make whipped cream, but /not/ as long as we would to make
butter.
There are tiny pieces of fat in the cream, and as we shake the bag, they’ll start to
clump together until the mixture becomes thick and creamy, just like ice cream should be.
If our salt water solution is as cold as if feels, that should take about five to ten
minutes.
Ready, Squeaks?
It’s getting there!
It looks like whipped cream now.
Just a little bit longer.
It’s looking a lot more like ice cream to me.
Let’s open it and check.
Make sure you have a spoon handy to taste test!
What do you think, Squeaks?
Tastes good to me!
We did it!
And we hope your science ice cream is delicious too!
Make sure to ask a grown up help you with your experiments and share your results!
Squeaks and I want to thank our friends at Google Making Science who helped us with this
experiment.
Let us know how your ice cream turns out by emailing us at kids@scishow.com
Thanks and we’ll see you next time here at the Fort!