As useless as a chocolate teapot: part 2

Dave Ansell and Ben Valsler test out the teapot made entirely out of chocolate, and find out if it can be used to brew a lovely cuppa.

Ben - Welcome back to the Naked Scientists chocolate teapot tea party. Dave, you've made yourself quite an impressive looking chocolate teapot here. can you run through how it was made?

Dave - Well, I first got a quantity of chocolate, about 1.3 kg of it. I then got a bowl, filled it to the half full of chocolate and put a smaller bowl inside to make the gap to put tea in and then I made a tube of chocolate by getting a tube of grease proof paper, sort of plastering the chocolate and putting more grease proof paper on the outside, putting that on the fridge and setting it.

Ben - So, that's formed our spout. How have you actually attached the two together?

Dave - Basically, just got molten chocolate and used it as a kind of glue. It welds the two together really nicely.

Ben - Excellent! Who would've thought that chocolate would make a good welding material? I can see also that you have a handle. Although, knowing that there's over a kilo of chocolate there, I'm not sure I'd trust it.

Dave - No. I think the handle is there mostly for aesthetic purposes.

Ben - Well, I suppose it's not a tea pot if it doesn't have a handle and a spout. So, I guess the next thing to do is just find out if we can brew some tea.

Dave - Indeed. I've got some couple of Earl Grey teabags here, open the lid, put the teabags in.

Ben - There's plenty of space in there. We should get at least two cups of tea out of this. Well, water has just gone off the boil so let's pour it in and see what we can do. [POURING] Well, it certainly hasn't melted through yet. I can see that you've even made a chocolate lid. Now, that looks very thin compared to the rest of the teapot, Dave. How confident are you that this lid is going to hold up?

Dave - The lid is probably the lowest level of confidence I have I'm afraid Ben

Ben - Well, with all that steam condensing on the underside of it, we shall have to see. So now, I guess we just sit back for a few minutes and let the tea brew for maybe 3 or 4 minutes.

[MUSICAL INTERLUDE]

Ben -   Well, it's already been 2 minutes since we poured the water in but unfortunately, we've had a bit of an incident with the lid. Dave, what's happening?

Dave - Well, hot air and steam rise. The heat is coming up then you got hot steam condensing on the bottom of this chocolate lid which is causing it to melt. So, the lid was very, very thin. It was rather an afterthought. If you want to make a chocolate teapot at home, make the lid more than 5 or 6 mm thick.

Ben - Okay, so the lid has melted through a bit, but the main bowl seems to still be very intact. How does it feel on the outside? Does it feel warm?

Dave - It still feels cold on the outside. So, it seems to be working quite well as an insulator. Obviously, the chocolate on the inside is insulating the chocolate on the outside. So, it's not melting. And now, for the moment of truth, we'll try and pour the tea out of the teapot.

Ben - I'm really, really impressed. The spout held firm. It does really look like tea as well. I expected it just to look like a chocolatey murky mess. Inside the bowl, it's all clearly melted but it's still pretty much bowl-shaped. It hasn't just become a puddle of chocolate.

Dave - I think what's going on is that although chocolate melts quite easily, when it's molten, it still got some structural integrity. It doesn't actually slump too quickly of its own accord unless you actually push it or it's trying to support its own weight like the lid was. Chocolate is made out of fat and fat is actually quite a good insulator. So, the molten chocolate was insulating the unmolten chocolate outside. So, the outside still stays solid and it didn't melt.

Ben - So, it's actually a layer of melted chocolate insulating the rest and this is why it didn't melt all the way through. It actually done a very good job.

Dave - Yeah. Chocolate is obviously better than you'd expect from making teapots out of.

Ben - I guess we better try the tea and see if it's any good. Cheers Dave!

Dave - Cheers! Ben.

Ben - That's actually not too bad, you know. It does taste a lot sweeter than I'd usually have my tea, but it's still hot, it's perfectly palatable and I think we've proved actually that you can make a teapot out of chocolate.