Make Instant Ice Cream! - Live experiments with jon chase - Head squeeze

Woohoo, yeah, 250,000 subscribers and that's all thanks to you and that's coming from the head Squeeze team, that's James, that's Greg, that's Huw, that's me, and don't forget the Sci Guide guys Tom and Andrew. Wow everybody. and we just want to celebrate by making ice cream. So you're gonna need a few resalable bags, one smaller than the other that you can see here. One that can fit into the other and you'll see what we need these for. We're gonna use 2350 millilitres of this milk. I'm using whole milk as you can see by the blue top. So we got sugar, we got milk, and that's four tablespoons of sugar. So you can have strawberry, you can have blueberry, have chocolate you can use coca power but we're going for some nice vanilla ice cream. So now we got out basic ice cream mix. So we gotta stick that into a small bag, oh yes! Right, so make sure you seal the smaller bag, Now obviously ice cream, we've got the cream, the creaminess, but now we need it to be iced. So into the bigger bag we want to stick loads of ice now we can see what temperature the ice is at here, you already know water turns into ice at zero degrees centigrade Celsius. So as you can see here it is at about minus one or minus two. So we're gonna take some of this and first we're gonna stick it in here. Right to that ice, we're gonna add a whole load of salt. Now if you're on a snowy day you might have seen that they add salt to the roads, by adding salt to the ice it actually melts it. we're putting in loads and loads of salt to this. There's our salt and ice mixture. Now all you got to do is stick that into the bigger bag. So now we're gonna stick our ice cream solution, our ice cream mixture, into the bag and stick the rest of the ice on top. Right so there we have it. We have bag of ice and salt, and inside it we have our milk and our sugar and our vanilla essence. As the ice is surrounding the ice cream mixture, what's happening is that it's absorbing the heat of the ice cream mixture, and also absorbing the heat from my hands which are making my hands freezing!! As the milk in the mixture in the ice cream mixture gets colder forms crystals inside, now of those crystals get too big, you'll get nasty big crystals and you won't get smooth ice cream. So you want to keep moving it around so that the ice cream is nice and smooth. Yeah! That is so much better, so much better, so as you can see the ice is melting and it's surrounding the bag inside with liquid, now the reason we added the salt is because the salt does a particular thing to ice. As we said it actually turns the ice back into a liquid at zero degrees. Then you add salt to water and it causes the freezing temperature of water to be lowered so that means you can actually have a liquid at below zero degrees. And what that helps to do is to cool down the collation quicker, cools down and causes the ice cream to cool down a lot quicker than it would if it was just at zero degrees. And the thing is if I just had the ice in there the ice would try and take the heat from the ice cream but the thing is you'd have little bits of air surrounding it. and that air doesn't conduct heat, as much as water does. And if we just add liquid water, without the salt it would only be at zero degrees which isn't as cold as when you got the salt in it which brings it down to below zero degrees. Almost minus 20 degrees Celsius, so by adding the salt it has reduced the temperature loads. We should have some lovely ice cream, right now obviously because i have a sweet tooth, I'm gonna scoop the ice cream out and give it a taste. Ahh, that's gorgeous, so once again here we have it, celebratory ice cream, thank you again for subscribing everyone 250,000 subscribers that is truly amazing! So if you make some by yourself at home let us know in the comments how it goes, and I'm just gonna go and share this with the rest of the team now, Huw James, Greg come and get some of this!