Introduction: Rainbow Ice Cream Float (from Scratch)

It's summer, and if you're like me, you might be craving a sip of the creamy, frothy, fizzy wonder that is an ice cream float!! Sure, you could settle for a classic, good ol' vanilla root beer float, perhaps something different like orange soda with a scoop of chocolate ice cream, or even a dollop of strawberry atop a bit of bubbly champagne if you're fancy. But what if you could have your indulgent, mouthwatering, tongue-tickling explosion of flavor with a dazzling, eye-catching, summon-your-inner-unicorn explosion of color; the taste of sweet, melty refreshment plus the magic of an exciting chemistry experiment? And enjoy the deep satisfaction of making it all with your own hands, from scratch, with love?

What's that? Do I hear your inner unicorn squealing with delight?? Allow me to show you the way...

Step 1: Ingredients and Materials Needed

Don't feel daunted by this big list! The process is actually very, very simple. This recipe serves about 10-12 people (or one person 10 to 12 times, if you don't want to share :)). Make sure to keep your whipping cream and milk cold, as this will help your ice cream become nice and fluffy.

  • 2 cups heavy whipping cream
  • 2 cups whole milk
  • 2/3 cup sugar
  • 1/3 cup light corn syrup (sweetened condensed milk also works)
  • 2 tablespoons dry whole milk powder
  • Red food coloring
  • Yellow food coloring
  • Zest of 2 medium lemons (optional)
  • 1 teaspoon cherry flavor extract (optional; I used cherry and vanilla but you can replace this with any flavor you want, like strawberry or raspberry, etc. and even use fresh fruit if you'd like.)
  • 1/2 teaspoon vanilla extract (optional)
  • Blue food coloring
  • Any clear soda (like Sprite-- I was trying to be healthy so I used berry flavored sparkling water)


  • Large bowl (glass works well)
  • Medium bowls
  • Whisk
  • Rubber spatula or large spoon
  • Ice cream machine (be sure to follow the manufacturer's instructions; some may require that you freeze the churning bowl a day in advance)
  • Serving glasses and straws or spoons

Step 2: Making Your Ice Cream Base

Start off by getting a large bowl and simply combine the heavy whipping cream, whole milk, sugar, corn syrup (or condensed milk), and milk powder in the bowl. The corn syrup and milk powder are there to help make your ice cream extra soft and smooth by reducing the amount of free water molecules that would freeze into chunky ice crystals.

Stir together these ingredients until the sugar, corn syrup, and milk powder are completely dissolved. I found that using a clear glass bowl allows you to easily see if you still have more sugar granules and undissolved syrup at the bottom of the bowl. Taste a bit of the mixture for sweetness and adjust the sugar to your liking (for instance, you may want it to be sweeter if your soda or sparkling water isn't particularly sweet or flavorful).

Step 3: Create Your Red and Yellow Flavors

Next, divide your cream mixture into two medium bowls and add red food coloring to one and yellow food coloring to the other. Be generous with the food coloring! The more vibrant your colors, the more dramatic the rainbow effect will be.

Once your ice cream bases are colored, decide how you want to flavor them. For the red, I went with cherry vanilla (using cherry extract and vanilla extract), but you could also do strawberry, raspberry, watermelon, etc. If you don't have or don't want to use flavoring extracts, you can try blending in a bit of fresh fruit juice, jam, or syrup; just make sure you don't add anything too watery or your ice cream may turn out icy.

For the yellow, I added lemon zest to make mine lemon flavored. Be careful NOT to put any lemon juice into the mixture, because anything too acidic will cause the cream to curdle. You could also go with melon, pineapple, orange, banana... be creative, and don't forget to taste and adjust the flavor to your liking! Or keep it all vanilla, whatever you prefer.

Step 4: Churning Your Ice Creams

This is where the magic begins, when your ice cream comes together! It's so satisfying to watch...

Read and follow the manufacturer's instructions carefully. Some ice cream makers may require that you freeze the freezer bowl hours in advance or complete other steps before use.

When you're ready, pour one of your colors of ice cream base into the machine and churn and freeze according to the instructions. Churning ice cream essentially incorporates air bubbles into the cream to make it light and fluffy, so I let mine run for a little longer to ensure a softer, lighter texture that would easily melt into the soda later. Depending on how good your ice cream machine is, it may help to occasionally scrape down the sides of the bowl with a rubber spatula or spoon so that the cream freezes evenly. Once your first ice cream reaches a smooth, soft-serve consistency, quickly transfer it into a container and store it in the freezer for later.

Then clean out the bowl of the ice cream machine (don't worry about getting it too clean, since the two colors and flavors will eventually get mixed anyways) and if needed, refreeze the freezer bowl for 20 minutes or so to make sure it's cold again. Pour in your other colored ice cream base and allow it to churn in the same way as the first one, then transfer it into a container to store in the freezer.

Although the ice creams are technically ready to use straight from the machine once they reach soft-serve consistency, I find that they melt too easily at this point and are better if stored in the freezer to firm up a bit, even just for 15 minutes.

Step 5: Preparing the Soda

Although dying the soda is a pretty simple step that we could have easily kicked out of the way in the beginning, you don't want to open the soda (or sparkling water) too early, because it's important that it retains as much fizziness as possible.

Open your soda bottle or can and generously stir in drops of blue food coloring to create a deep, bright blue hue.

Step 6: Making the Float

Now it's time to assemble the float and watch the rainbow happen!

Pour the blue soda into a tall glass. Then top it with a large scoop of the red ice cream and a large scoop of the yellow ice cream. Sit back, listen, and ooh and ahh as you watch fizzy, fluffy, foamy clouds of color emerge at the top, then dig in and enjoy!

Step 7: Admire the Rainbow

And that's how you make a rainbow ice cream float! Yup, it's as easy as mixing, pouring, more pouring, some scooping, and some more mixing.

In addition to the red ice cream, yellow ice cream, and blue soda, the red and yellow combine to create orange, the yellow and blue combine to create green, and the red and blue create purple and indigo (although some colors might be more prominent than others in the float that I photographed-- it helps to use more food coloring).

Thanks for reading!

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