Ah, December. Longer nights, shorter days, colder winds and the first real snow fall . But, what better month to use your science skills to make your very own ice cream?
It might seem an odd time of year to make an icy treat but there is a good reason to choose a winter month for this activity: snow! Making ice cream is all about the science of heat transfer – getting heat transferred out of the liquid cream and turning that liquid into a solid. To get started, you’re going to need to gather the following materials:
Remove your candy canes from their wrappers, place them in one of the sandwich bags and seal. Fold the towel over a couple of times and use it to cover a hard surface like a kitchen counter. Place the sandwich bag of candy canes on top of the towel and use the hammer to break up the canes into smaller pieces. Transfer the candy cane pieces into the second sandwich bag and add the cream and sugar to the mix. Gently squeeze as much air from the bag as you can and seal it up good and tight.
Grab your large freezer bag and fill it about half-full with ice cubes or snow and then add in the rock salt. Next place your sandwich bag of cream, candy canes and sugar into the salty, icy large freezer bag and seal. Make sure you have your mittens on and then get shaking! That’s right the next part is all about shaking the freezer bag every which way for around 15 minutes, long enough for your cream to turn to ice cream. Once your time is up remove the sandwich bag from the salty, icy water and give it a quick rinse under the cold tap. Open the bag, grab a spoon and dig into the fruits of your science!
Watch this video for more direction http://www.youtube.com/watch?v=rnZ2EwDpPE4&list=PLqg5wOPPT4L82QICIBsQMrNEFxk0Csx71&index=5
What’s happening in this home-made ice cream experiment? The salt helps to do two things: it speeds up the melting of the ice and also lowers the temperature that ice freezes at, which means that the melted ice water can be colder than zero degrees Celsius! This super-cool, salty ice water is really exceptional at absorbing what little heat is in the cream, speeding up the process of freezing it into dessert. Just don’t get the salt in your ice cream!
Keep an eye open for our monthly ice cream social night. On periodic Wednesdays, we stage an exciting presentation in our Theatre where a Discovery Centre interpreter will freeze some delicious ice cream using liquid nitrogen instead of ice. It’s super cool! Check out our website for dates and details.