Sweet future for bendy chocolate

If you love chocolate but think bars are boring, a team of scientists from Cambridge University has developed the answer to your prayers: elastic chocolate that can be bent into any shape without heating and without losing its taste.

The new technique, which compresses the chocolate to 100 times atmospheric pressure, could mean that the bar of the future is knotted, plaited, curled, curved or just plain wiggly.

Nestle, the Swiss giant which owns Rowntree, has first choice of exploiting the discovery but is keeping its ideas well wrapped for the moment."It is commercially sensitive, and we are not prepared to discuss how we might use it," a spokesman said.

The phenomenon was discovered by Dr Malcolm Mackley, of the university's department of chemical engineering. He specialises in polymer extrusion technology, used in plastics manufacturing, but became interested in other applications during a visit to a chocolate factory. After confirming two years ago that chocolate could be forced through nozzles without melting, he has been studying how the effect occurs.

"I spent about 20 years studying plastics before coming onto this. I think this is potentially more interesting so I am glad I approached it this way," Dr Mackley said.

Simon Crook, a PhD student on the project, said: "Chocolate is interesting because under pressure it behaves somewhere between a paste, such as toothpaste, and a polymer. Basicaly, you take a huge steel syringe and force the chocolate out of it. It doesn't melt but it remains malleable for about half an hour before it sets. I spent this morning tying knots in some." Once set, it behaves like normal chocolate.

Previously, manufacturing odd shapes has called for the moulding of molten chocolate. But this limits the possible shapes: "It's impossible to manipulate molten chocolate - it's like trying to tie a knot in water," Mr Crook said. The heating must also be carefully controlled in order to keep the product's taste. But because the pressure method does not involve heating, it does not affect taste.

Sadly, the scientists have not found the answer for chocoholics in search of the ultimate, fat-free fix. "The key to this process seems to be the fats, which lubricate the process somehow," says Mr Crook. So there is still only one sort of chocolate that will not make you fat - the sort that you do not eat.