Summer is the perfect time for outdoor science experiments with kids, and my family’s favorite kind of experiment is the one we can munch on afterwards. The other day my kids and I made homemade slushies. Not the ones you make in the blender, but really cool slushies you make with frozen salt water and fruit juice. It is the perfect ice cold dessert to enjoy on a hot summer day, plus there is a little science lesson involved for the kids.
To get started, first make ice cubes by adding 1/2 cup of water and 1 teaspoon of kosher salt to a zip-top bag. Add a little food dye to color the water so you can see it clearly. It makes it more fun! Seal the bag well and freeze the water until completely solid, about 6 hours.
Choose some of your favorite fruit juices to be the flavor of your smoothies. We used fruit punch and orange juice. They are our absolute favorite flavors. Add about 1 cup of juice to a large cup or jar with a lid (you can also use a big freezer bag).
Take your bag of frozen ice water out of the freezer and into the glass with the juice. Carefully seal the top.
Now, let your kids go crazy! Let them shake up the juice and you’ll see that within a few minutes the juice will freeze up and turn into a slushie. No syrup and no blender required!
It took my daughter about 3 minutes of shaking to get her smoothie to snow cone consistency. The ice crystals formed nicely and it was still thin enough to suck up through a straw. My kids LOVED the activity as a whole. As my daughter said, they were like juice sorbet!
Let your kids enjoy the slushies, but be sure to also explain how it works! The science lesson: salt enables the ice cube to stay frozen long enough to begin to freeze the liquid surrounding it. A regular ice cube would just melt away and dilute the juice before it had a chance to freeze.More On