Author: Maddie Van Beek
This summer has been HOT! When it gets this warm outside, it's time for some frosty treats! Today we're going to make our own homemade ice cream and homemade slushies WITHOUT using a freezer! We'll use the same scientific principles for both activities, so let's get learning!
The History of Ice Cream:
We shared a blog last summer about ice cream, and this gives some great background on the history behind this tasty treat. Check it out here: https://www.discoveryexpresskids.com/blog/cool-down-with-ice-cream
Today, we're going to focus on the science behind homemade ice cream. How do you get the ingredients to freeze without a freezer?
The Science:
Normal water freezes at 32 degrees Fahrenheit. Your goal is to get your ice cream mixture below that temperature so it will freeze. The problem is, just packing ice around the mixture won’t do the trick. Why is that? The ice will begin to melt at room temperature, so while it will definitely cool the mixture down, it won't get it cold enough to freeze the mixture. That leads us to our secret ingredient: salt!
If you add salt (sodium chloride) to ice, it can drastically lower the temperature to almost zero degrees Fahrenheit (0°F)! THAT'S cold enough to quickly begin freezing your ice cream mixture. How does salt do that?!
Take an ice cube out of your freezer and place it on the table. Sprinkle a little salt onto the ice cube and watch carefully. It quickly begins to melt! That's why you see people sprinkling salt on icy roads in the winter--salt lowers the freezing temperature of water. Usually, water freezes at 32 degrees/ice begins to melt at 32 degrees Fahrenheit (32°F). When you add salt to water, it has to be much colder in order to freeze. Thus, ice that would normally remain frozen on a sub-32 degree day begins to melt when you add salt.
It seems strange to melt our ice in order to get our ice cream mixture colder, but remember, even though the salt causes ice to melt, it actually is lowering the overall temperature. The subsequent water is still super cold, it's just liquid instead of solid. So you'll see the salt begin to melt your ice, but it's essentially cooling down your ice cream mixture inside!
Now that you know the science behind our activity, let's get to it!
The Classic: Homemade Ice Cream
YOU WILL NEED:
* Cream
* Vanilla
* Sugar
* Gallon zip-top bag
* Quart zip-top bag
* Ice
* Salt
Here's what to do!
1. Measure 1 cup cream (Half and Half), 2 tablespoons sugar, and 1/2 tsp of vanilla extract into your smaller zip-top bag. Seal it so it is tightly closed!
2. Measure about 6 cups of ice and 1/2 cup salt into your gallon size zip-top bag.
3. Place the small bag of your ice cream mixture into the larger bag of ice and salt.
4. Seal the large zip-top bag and start shaking! Don't throw the bag or shake it too hard--you don't want any leakage!
5. After just a few minutes, you should feel the mixture begin to get firmer. Once it feels like a thick enough consistency, open your large bag and remove the small one.
6. Open your small bag and enjoy! You can carefully dump your ice cream into a dish and top with syrup or sprinkles, or you can just eat it right out of the bag!
Extension:
Use other ingredients to make healthier frosty treats! Try using yogurt instead of cream. Does it take more or less time to freeze? Another great trick is using blended bananas! It gives you a great, creamy texture without all the fat and added sugar.
Banana “Nice” Cream
* 2 ripe bananas
* Ingredients of your choice! (I used mint extract and dark chocolate chips)
* Gallon zip-top bag
* Quart zip-top bag
* Ice
* Salt
This summer has been HOT! When it gets this warm outside, it's time for some frosty treats! Today we're going to make our own homemade ice cream and homemade slushies WITHOUT using a freezer! We'll use the same scientific principles for both activities, so let's get learning!
The History of Ice Cream:
We shared a blog last summer about ice cream, and this gives some great background on the history behind this tasty treat. Check it out here: https://www.discoveryexpresskids.com/blog/cool-down-with-ice-cream
Today, we're going to focus on the science behind homemade ice cream. How do you get the ingredients to freeze without a freezer?
The Science:
Normal water freezes at 32 degrees Fahrenheit. Your goal is to get your ice cream mixture below that temperature so it will freeze. The problem is, just packing ice around the mixture won’t do the trick. Why is that? The ice will begin to melt at room temperature, so while it will definitely cool the mixture down, it won't get it cold enough to freeze the mixture. That leads us to our secret ingredient: salt!
If you add salt (sodium chloride) to ice, it can drastically lower the temperature to almost zero degrees Fahrenheit (0°F)! THAT'S cold enough to quickly begin freezing your ice cream mixture. How does salt do that?!
Take an ice cube out of your freezer and place it on the table. Sprinkle a little salt onto the ice cube and watch carefully. It quickly begins to melt! That's why you see people sprinkling salt on icy roads in the winter--salt lowers the freezing temperature of water. Usually, water freezes at 32 degrees/ice begins to melt at 32 degrees Fahrenheit (32°F). When you add salt to water, it has to be much colder in order to freeze. Thus, ice that would normally remain frozen on a sub-32 degree day begins to melt when you add salt.
It seems strange to melt our ice in order to get our ice cream mixture colder, but remember, even though the salt causes ice to melt, it actually is lowering the overall temperature. The subsequent water is still super cold, it's just liquid instead of solid. So you'll see the salt begin to melt your ice, but it's essentially cooling down your ice cream mixture inside!
Now that you know the science behind our activity, let's get to it!
The Classic: Homemade Ice Cream
YOU WILL NEED:
* Cream
* Vanilla
* Sugar
* Gallon zip-top bag
* Quart zip-top bag
* Ice
* Salt
Here's what to do!
1. Measure 1 cup cream (Half and Half), 2 tablespoons sugar, and 1/2 tsp of vanilla extract into your smaller zip-top bag. Seal it so it is tightly closed!
2. Measure about 6 cups of ice and 1/2 cup salt into your gallon size zip-top bag.
3. Place the small bag of your ice cream mixture into the larger bag of ice and salt.
4. Seal the large zip-top bag and start shaking! Don't throw the bag or shake it too hard--you don't want any leakage!
5. After just a few minutes, you should feel the mixture begin to get firmer. Once it feels like a thick enough consistency, open your large bag and remove the small one.
6. Open your small bag and enjoy! You can carefully dump your ice cream into a dish and top with syrup or sprinkles, or you can just eat it right out of the bag!
Extension:
Use other ingredients to make healthier frosty treats! Try using yogurt instead of cream. Does it take more or less time to freeze? Another great trick is using blended bananas! It gives you a great, creamy texture without all the fat and added sugar.
Banana “Nice” Cream
* 2 ripe bananas
* Ingredients of your choice! (I used mint extract and dark chocolate chips)
* Gallon zip-top bag
* Quart zip-top bag
* Ice
* Salt
 |  |
Here's what to do!
1. Put two ripe bananas in a food processor or blender, and blend until smooth. Add 1/2 avocado for a creamier texture or some cashews for something more hearty.
2. Add your mix-ins. I picked mint extract and dark chocolate chips, but peanut butter, nuts, or fruit would also be great! You can blend them in, or you can add afterwards.
1. Put two ripe bananas in a food processor or blender, and blend until smooth. Add 1/2 avocado for a creamier texture or some cashews for something more hearty.
2. Add your mix-ins. I picked mint extract and dark chocolate chips, but peanut butter, nuts, or fruit would also be great! You can blend them in, or you can add afterwards.
3. Pour your blended bananas into the quart zip-top bag and seal.
4. Put your ice and salt in the gallon bag, then place the small bag of your ice cream mixture inside. Seal the gallon bag and start shaking! You’ll notice the ice begins to melt pretty quickly!
 |  |
Within about 5 minutes, my nice cream was ready to eat!
 |  |
5. Enjoy!
Freezerless Slushy
* YOU WILL NEED:
* Fruit juice
* Gallon Zip-top bag
* Quart Zip-top bag
* Ice
* Salt
Here's what to do!
1. Measure about 1 cup of fruit juice into a quart sized zip-top bag and seal shut.
2. Repeat steps 2-6 from the homemade ice cream activity.
3. Enjoy!
Suggestion:
If you're an athlete or using this recipe for after working out, use an electrolyte sports drink so you have a frosty recovery treat! Even if you’re not working out, it’s super important to stay hydrated in this hot weather. This electrolyte slushy is just more fun :]
Before shaking:
Freezerless Slushy
* YOU WILL NEED:
* Fruit juice
* Gallon Zip-top bag
* Quart Zip-top bag
* Ice
* Salt
Here's what to do!
1. Measure about 1 cup of fruit juice into a quart sized zip-top bag and seal shut.
2. Repeat steps 2-6 from the homemade ice cream activity.
3. Enjoy!
Suggestion:
If you're an athlete or using this recipe for after working out, use an electrolyte sports drink so you have a frosty recovery treat! Even if you’re not working out, it’s super important to stay hydrated in this hot weather. This electrolyte slushy is just more fun :]
Before shaking:
After only 2 minutes of shaking:
After two more minutes:
Ready to eat!
