Science Smarts: Ice cream for Mother’s Day

By Patty Rooks on May 8, 2021.

I hope you have not forgot that this weekend is Mother’s Day? Many of us have someone special in our lives and it is always nice to show them how much we care about them. I always say it is the little things that people do for me that I greatly appreciate. This week, I am going to share a special treat children of any age can do for the loved one in their lives. If they are like me, they are going to love this! Let’s get started!

Remember to ask an adult before doing this experiment

Materials

• Two coffee cans – one large and one smaller so it will fit in the large one

• Duct tape

• Ice

• Coarse (pickling) salt

• Measuring cups

• Measuring spoons

• Sugar

• Heavy (whipping) cream

• Milk

• Vanilla

• Mixing spoon

Procedure

• Place small coffee tin inside of the large tin.

• Pack ice evenly between the two cans about ¾ of the way up the sides.

• Measure 175 mL (3/4 cup) milk into small can.

• Measure 250 mL (1 cup) of heavy cream. Pour into the small can.

• Add 80 mL (1/3 cup) sugar.

• Stir well.

• Add 5 mL (1 tsp) of vanilla.

• Make sure this is combined well and sugar has been dissolved. You may have to stir it a bit.

• Put the lid on the smaller coffee can and secure in place with duct tape.

• Fill the rest of the large coffee can with ice. It should be all of the way up the sides and perhaps on top of the small can.

• Sprinkle 250 mL (1 cup) salt over the ice.

• Put lid on large can and secure with duct tape.

• Shake, kick, and roll the can for at least 15 minutes and then check.

• If the ice cream is not hard yet, you may have to add more ice and salt and shake some more. Make sure you put the lid back on!

• Enjoy!

What is going on?

The same reason many cities use salt on icy roads in the winter is why we are using salt with the ice to make ice cream. As you know, salt makes ice melt. When salt and ice mix, the freezing point of the ice is lowered causing the ice to melt. Where is the heat coming from to cause the ice to melt you might wonder. Well, the heat that causes the ice to melt is from the warmer cream mixture in the other container. This is why you have to keep shaking or kicking the can – by shaking it up, you’re continually moving the warmer cream mixture from the middle of the can to the outside where it can begin to freeze evenly. By lowering the temperature that the ice freezes, we are able to create temperatures below 0°C which is necessary for the cream mixture to freeze into delicious ice cream.

Do not forget to register for our “Explosive Science” event next week in conjunction with the Redcliff Public Library. Space is limited so do not delay contacting them!

Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismedhat.com, Tweet or follow us @PraxisMedHat, or friend us on Facebook. Address: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403.527.5365, email: praxis@praxismh.ca.

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