skip to primary navigationskip to content

Flexible Chocolate

An interactive public lecture 

I think it was Dawn French who said "There are two types of people - those who like chocolate and those who lie". Everyone likes chocolate and the bendy chocolate lecture on Saturday 13 March 1999 filled the Babbage lecture theatre to capacity - that's around 300 people. It was presented by Dr Malcolm Mackley and Robert Marshall from the University of Cambridge, Department of Chemical Engineering.

chocolate The lecture was intended for everyone aged 12 or over, though there were some smaller children there too, and they enjoyed the messier experiments.

Malcolm and Robert began with a description of what chocolate is and where it comes from, which was the cue for a large globe to be rolled down the aisle.
choccie Then, after a short discussion of the physics and chemistry of chocolate, they got on to the experiments. Volunteers who helped with experiments were given Easter eggs and almost every child in the audience wanted to be a volunteer. The first "victim" demonstrated the melting point of chocolate by sucking a probe coated in chocolate. A large screen showed the temperature in her mouth


The messiest experiment showed the traditional way of making chocolate into shapes. That is, you melt it, pour it into moulds and wait for it to cool down and set. At the end of the lecture, this mess still hadn't cooled enough to be turned out of the mould.


The new way of making chocolate into interesting shapes is to extrude it. This toy shows the idea of extruding - in this case squirting plasticene through a small hole.

choc More volunteers then helped to work the machine that makes real bendy chocolate

and this is bendy chocolate....





RSS Feed Latest news

Alumnus Professor McKinley elected Royal Society Fellow

Apr 23, 2019

Alumnus Professor Gareth McKinley among the 51 distinguished scientists elected as new Royal Society Fellows for his exceptional contribution to science.

Dr Vassiliadis celebrates the contributions of Roger W.H. Sargent at memorial event

Apr 17, 2019

Dr Vassiliadis contributed a talk on optimal control in chemical engineering at a memorial event for Roger W.H. Sargent, founder of process systems engineering.

A chemical garden that’s also a chemical clock

Apr 12, 2019

Research from our Cardoso lab and their colleagues in Spain, published in Angewandte Chemie, combines two classic demos in one beautiful example of active fluid dynamics.

View all news

Upcoming events

CEB Research Conference 2019

Jun 25, 2019

Department of Chemical Engineering and Biotechnology, Philippa Fawcett Drive, Cambridge, CB3 0AS

Machine learning and AI in (bio)chemical engineering

Jul 08, 2019

Department of Chemical Engineering and Biotechnology, Philippa Fawcett Drive, Cambridge, CB3 0AS

Stokes200 Symposium

Sep 15, 2019

Pembroke College, Cambridge

VPF8 Viscoplastic Fluids: from Theory to Application 2019

Sep 16, 2019

Jesus College, Cambridge

Upcoming events