How does ice cream making work? The key is getting the mixture to mix around while surrounded by salt and ice. Salt is a special ingredient that lowers the freezing point of water (ie. it melts the ice to make colder than ice water!!).
I think J's school has made ice cream with the kids, but I wanted to do it on my own with him. I decided to purchase the ice cream ball from Amazon (affiliate link) (as a bday gift to myself - thanks to my bro and sis-in-law).
The ball came with a simple recipe: 1 pint of cream (we used heavy whipping cream), 1/3 cup + 2T of sugar, and 1.5 tsp of vanilla.
After filling the ball portion with crushed ice and rock salt (Safeway had a box of special ice cream making salt for $0.99 - it's not food grade, but it's great to use in experiments like this since it won't be directly touching what we'll eat):
we mixed the ingredients in a separate bowl:
and poured into the ice cream compartment:
Don't forget to seal both compartments!
Then we got to tossing/rolling.
The book that came with the ice cream ball had approximate freeze times for ice cream. The heavier the cream, the faster the freezing time. Since we used the 2nd heaviest cream (heavy whipping cream), we decided 20 minutes would be a good time based on their recommendation.
And this is what we got after 20 minutes of "play":
|A little soupy|
I was warned by a few parents at the last Science Saturday when brainstorming ideas for the next Science Saturday that ice cream making does take a long time, which is why I'm currently testing the ideas. Really, the ball took 20 minutes and it was soupy (but still good enough to eat as ice cream). Keeping J's attention that long was tough. Plus, it's too expensive to get enough ice cream balls to make it worth while for a Science Saturday event.
However, I'm still determined to make ice cream making work on a larger scale for a Science Saturday event. Tonight, we had much more success just making ice cream in a baggie. I have pictures, video, directions, and activities surrounding baggie ice cream that I'll post later in the week. Stay tuned.
Until then, I hope you are enjoying your summers thus far!
*Make ice cream in a baggie