Posted on Sunday, July 19th, 2020


[Mara sitting on the floor in front of a fan.]

Joanne: Uh, hey Mara, what you doing?

Mara: I'm melting away it is so, so hot this summer. 

[Joanne kneels down to talk to her.]

Joanne: It is pretty hot this summer but the good news is you're not actually melting 

Mara: I feel like it. Could I get some ice cream?

Joanne: Ice cream! It's like 9 30 in the morning, but if we make our own ice cream for today's episode of ask me anything science edition, I guess I could make an exception.

Mara: Yay!

Joanne: Let's get started!

[Cut to Guelph Physics logo, swoosh sound.]

[Cut to kitchen bar with Mara and Joanne, sitting at the counter with ice cream ingredients.]

Joanne: Here's what you need; about a cup of half and half or cream. We're gonna put that in this small Ziploc bag. We're gonna add half a teaspoon of vanilla to that. You pour it over that. Just in case a little bit more all right perfect. Thank you! And put that in there too and we're going to add two tablespoons of sugar to this mix and then we're gonna seal up the bag. One and another one please, two, Alright now we're gonna seal this bag make sure it's closed. Alright now in our big bag we're going to take about three or four cups of ice and a third of a cup of course salt. Now we're gonna take our cream mixture put it in the big bag
and close it up nice and tight. 

Alright closed?

Mara: Uh hm. Okay so what's the plan here exactly can we just put this mixture and freeze it?

Joanne: Well we could except that it wouldn't really give us the texture that we like in ice cream and it takes a long time. I mean think about how long it takes water to turn to ice when you want a nice cold drink. So we're gonna speed things up because one we're a little impatient and two the texture is actually nicer smoother if it cools down quickly.

Mara: Cool. You get it because it's cold.

[Joanne rolls her eyes.]

Joanne: Right, so what we need is, we want our warm substance, which is a liquid to become a solid. So, we want it to cool down. So, we want to transfer some of the energy from the warm substance to big bag which is the cold substance.

Mara: How do we do that? 

Joanne: Shake it baby!

[Music throughout.]

[Cut to Mara shaking the ice cream bag on a swing outside.]

[Cut to Mara shaking the ice cream bag upside down on the couch.]

[Cut to Mara shaking the ice cream bag on a tread mill.]

[Cut to Mara shaking the ice cream bag outside, hanging upside down on a play structure.]

[Cut to Mara shaking the ice cream bag outside, in a tree house.]

[Cut to Mara shaking the ice cream bag outside, bouncing on a trampoline.]

[Cut to Mara shaking the ice cream bag outside, while playing badminton.]

[Cut to Mara shaking the ice cream bag outside, while cutting the grass on a riding lawn mower.]
Joanne: Okay it's been about 10 minutes let's see what we've got inside there. Looking like it's solid. Okay you wanna put it in a bowl here. Oh yeah that's looking great. Okay give that a try. 

Mara: Mmm.

Joanne: What do you think? 

Mara: Breakfast of champions. 

Joanne: Yeah, that's not going to be happening every day, just for you know for the record.

Mara: Why do we have to put um salt in the ice?

Joanne: Oh, good question. So, when the ice comes out of the freezer it's at minus 20 degrees Celsius, but it warms up really, quickly. So, if we didn't put salt in there the ice would warm up all the way to zero degrees Celsius, where it starts to melt and turn into water. So, it would stay at about zero degrees Celsius for a little while. While it transfers heat from the warmer cream into the mixture. If we add salt, the ice will warm up from -20 to about -3 or -4 with the salt in there. So, we end up with the large bag containing a mixture of salt and ice and water at around -3, -4 degrees which is a more efficient heat transfer from the warmer cream and it cools down faster.

Mara: Efficient heat transfer is delicious!

Joanne: And if we were at work I'd be able to do it even faster with some liquid nitrogen. Liquid nitrogen holds its temperature at about -200 degrees Celsius. So, if we mix the cream in with that, it would turn from a liquid to a solid almost instantly.

Mara: Wow! You guys could also try different flavors like if you added um some chocolate syrup to it you can make chocolate ice cream. Happy national ice cream day and thanks
for watching ask me anything science edition!


[Cut to Guelph Physics Logo.]


[Cut to Mara shaking a bag of ice cream mixture in the kitchen. Text over video reads; And a very special thanks to the grade 2 & 3 students from JD Hogarth PS who made ice cream with us!]

[Cut to black screen with text, But none of this would have happened has we not been inspired by the work of Guelph Physics alumni, Joshua Mogyoros, who showed us the ice cream he made for HIS students!]

[Cut to Joshua seated, wearing a baby-blue tuxedo shirt and jacket.]

Joshua: Hello. Ah all right. So, let's try to make ice cream. Some milk, some cream.

[Background music throughout.]

Some sugar. Some salt. Some vanilla extract. Some gloves. A small and large Ziploc bag. I didn't have a very good ice cube tray so, I got a bowl and I froze ice in that bowl a few times.

I'll go get the ice this is the ice I'm gonna be using.

[Joshua leaves the frame and returns with 4 large bowl shaped pieces of ice]


I recommend uh that you use an ice cube tray that'll be a lot easier. This is this is really, cold! I’m gonna go break up this ice one sec it'll be two seconds I promise I won't be, I won't be long. I'll be right back.

[Joshua leaves frame with the ice.]


[Joshua returns to frame with the ice, outs down the ice and starts to put on thick work gloves.]

We're off to a great start. How are these two left gloves? All right I’ll, I'll be back. 

[Josuha leaves frame.]

[Cut back to Joshua seated holding a bowl of broken up ice.]

There's a bunch of ice. We take our small Ziploc bag and we're gonna put one cup of cream, one cup of milk, a tablespoon of sugar and one and a half teaspoons of vanilla extract. Throw that in there. Vanilla extract we'll do, ooh that smells very nice. One, whoops, two, three. 

[Tastes vanilla from the sppon.]

It doesn't taste as good as it smells. I mean, I wouldn't try that. One cup of cream.


Perfect! One cup of cream. 

[Reaches out to tilt camera down at cream and the rest of the work surface.]

It's probably more interesting than I am. One cup of milk. There we go. I'm sure that'll all get mixed up nicely, in the mixing process. Let's make sure this is closed very, very, well. Otherwise, that will also be a disaster a bit of a test. All right that looks safe. Put this in here to make sure there's enough room for it. 

[Adds small bag with mixture to the big bag.]

And we'll start filling it up with ice and then we'll add our salt. All right let's save some room to be able to shake that is very cold.

[Leans forward and knocks bag over. Shouts!] 

Eight tablespoons of salt. One this is not very exciting, two, three, four, five, six, seven, all right eight. Make sure this is closed really well and then we're gonna shake it for what was it five to seven minutes…

[Shaking bag.]

I'm just, I'm just gonna do this for a while. How long ago did I start?



All right should we try this out? What? Science! Check that out. Ice cream!


Whoa that's crazy okay. Some ice cream, hmm that's pretty good. Some strawberry Quick. Don't knock it till you try it!


[Shows bowl of ice cream with strawberry sauce.]

Put that on the gram right there. This is this is really good. I'd say, all right I have brain freeze. I'd say it's a success.


[Screen goes black.]


Dr. Joanne O'Meara and junior scientist Mara tackle this tasty treat, and stick around for a guest appearance by former Guelph Physics alumni Josh!

Find related news by keyword

News Archive