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Kitchen Chemistry: Homemade Ice Cream Sundae Bar

Recipes

You can make a homemade ice cream sundae bar—with all the fixings—without any fancy equipment. And besides being easy and delicious, these recipes are a great way to introduce your daughter to the chemistry of frozen treats and their toppings!

Here are some concepts you and your girl can learn about together as you whip up the recipes below:

Emulsion: a mixture of different substances that don’t normally combine, like fat particles and water.

Maceration: the process of softening something by soaking it in a liquid.

Melting Point: the temperature at which a food changes from a solid to a liquid.

These recipes walk you through how to make a sundae bar with vanilla ice cream,  strawberry sauce, and chocolate candy shell topping. Of course, feel free to add your own twists and combinations!


Ice Cream Chemistry
Emulsions

making-ice-cream

 

Most traditional ice cream is made using an ice cream maker, which constantly churns a mixture of cream, sugar, and flavoring (and sometimes eggs) as it freezes. This combination of fat (from the cream) with the water, sugar, and flavoring is called an emulsion—a combination of two liquids that normally don’t mix.

As the ice cream continues to churn, tiny air bubbles become trapped between fat globules. This air is important because it’s what makes ice cream fluffy and soft. Most ice cream is made up of about 30 to 50 percent air! The constant stirring also helps break down ice crystals before they get too big, which keeps the ice cream from being becoming hard and gritty.

ice-cream mixer
ice-cream science

 

Our recipe is a little different than traditional ice cream because we use evaporated milk instead of cream, and we use a blender instead of an ice cream maker. The result is fluffier and lower in fat than traditional ice cream, similar to soft-serve ice cream. Yum! 

Vanilla Ice Cream

 

You will need:

1 (12-ounce) can evaporated milk

1 cup powdered sugar

2 teaspoons vanilla extract

Directions:

  1. Place the evaporated milk in the refrigerator overnight. Once chilled, pour the milk into a blender and blend on high for 45 seconds. (You can use an electric mixer or a whisk if you don’t have a blender.) Add the powdered sugar and vanilla extract. Blend on high for 30 seconds.
  2. Pour the mixture into a food storage con­tainer, cover, and place in the freezer for 1 hour. After 1 hour, remove the container and use a whisk to stir the mixture a few times. Place the container back in the freezer.
  3. Repeat the freezing and stirring in step 2 two more times. Then freeze the mixture over­night. The final texture of the ice cream will be somewhat soft. Scoop some into a bowl to enjoy, or store the ice cream in a covered container in the freezer.

 

 

Most traditional ice cream is made using an ice cream maker, which constantly churns a mixture of cream, sugar, and flavoring (and sometimes eggs) as it freezes. This combination of fat (from the cream) with the water, sugar, and flavoring is called an emulsion—a combination of two liquids that normally don’t mix.

As the ice cream continues to churn, tiny air bubbles become trapped between fat globules. This air is important because it’s what makes ice cream fluffy and soft. Most ice cream is made up of about 30 to 50 percent air! The constant stirring also helps break down ice crystals before they get too big, which keeps the ice cream from being becoming hard and gritty.

Our recipe is a little different than traditional ice cream because we use evaporated milk instead of cream, and we use a blender instead of an ice cream maker. The result is fluffier and lower in fat than traditional ice cream, similar to soft-serve ice cream. Yum! 


Strawberry Sauce Science
Maceration

strawberry science

 

There’s nothing like fresh strawberry sauce drizzled over homemade ice cream. The secret to our recipe is maceration, which is when you soften something (often fruit) by soaking it in a liquid. When you add sugar to strawberries, it causes the berries to release their own liquid. (Strawberries are 92 percent water!) The result is softened berries in a sweet syrup, without adding any additional liquid. Heating the berries in the microwave softens the berries even more.

Strawberry Sauce

 

You will need:

1 pound fresh strawberries

1 tablespoon granulated sugar

2 teaspoons vanilla extract

Directions:

  1. Wash and drain the strawberries. Remove the tops and cut the strawberries into quarters.
  2. Place the cut strawberries in a large microwave-safe bowl, and stir in the sugar. Let the berries and sugar sit at room temperature for about 30 minutes.
  3. After 30 minutes, stir the strawberries. Place the strawberries in a microwave and heat on high for 12 minutes, stirring after each minute. Use a pastry cutter or potato masher to crush the strawberries, and stir again. Serve the strawberry sauce warm over ice cream.

 


Chocolate Candy Shell Chemistry
Melting Point

chocolate sauce temperature

 

Warm chocolate shell topping seems magic because it starts as a liquid and quickly hardens when you drizzle it onto cold ice cream. This “magic” has to do with the chocolate’s melting point, which is the temperature at which a substance changes from a solid to a liquid. Let’s consider how the ingredients of this topping—chocolate chips and coconut oil—make this possible:

Chocolate chips are made from cocoa powder, sugar, and a fat called cocoa butter. Depending on how much cocoa butter (fat) is in the chocolate, the melting point of chocolate is about 85 degrees Fahrenheit.

Coconut oil comes from the white “meat” inside coconuts. Compared to other oils such as olive oil or vegetable oil, coconut oil is high in fat. The large amount of fat causes the oil to have a melting point of about 76 degrees Fahrenheit. (This is much higher than water and most oils.) Most of the time, coconut oil is a soft paste. If it’s stored in a warm place, the paste turns into a liquid.

strawberry science
strawberry science

 

Most ice cream is between five degrees and ten degrees when you start eating it. When you pour the melted chocolate and coconut oil mixture on cold ice cream, the candy freezes very quickly. Remember, the temperature doesn’t have to drop very much for coconut oil to turn to a solid. The cold ice cream speeds up this process.

Chocolate Candy Shell Topping

 

You will need:

2 cups chocolate chips

6 tablespoons coconut oil

 

Directions:

  1. Place the chocolate chips and coconut oil in a microwave-safe bowl and stir together.
  2. Heat the mixture in a microwave on high for 1–2 minutes, stirring every 30 seconds until melted. Stir the mixture until it’s smooth. Then let it cool slightly.
  3. Pour the chocolate over ice cream. It will harden and form a candy shell! Store leftover topping at room temperature in a sealed container. If it hardens, reheat the topping for 10–15 seconds to melt it again.

 

For another kitchen chemistry project, check out Kitchen Chemistry: The Science of Flavor.

 

 

Illustrations by Emily Balsley. ©2019 American Girl. All American Girl marks are trademarks of American Girl.

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