Self-chilling beer

It is every beer lover's summer nightmare - stuck in the middle of a park with the sun warming your drink. Thankfully, scientists have come up with a solution: the self-cooling beer can.

Slightly longer than a normal drink can, it simply needs a twist to cool its content down. It can, its inventors claim, cool a beer to the perfect temperature of 3C within three minutes.

The I C (Instant Cool) Can works by using water evaporation. The top half is surrounded by a layer of watery gel. The base contains a water-absorbing material in a vacuum, and a special heat-absorbing chamber.

When the bottom is twisted, a seal between the two halves is broken. The vacuum draws the gel, and the heat, into the base. The gel is absorbed by the material, the heat is absorbed by the chamber - and the drink gets cold.

Trials showed that on average, the temperature of the liquid in the can fell 16C when the system was activated. Drinks stayed cool for up to an hour. The cans are already being tested by two large British brewers, who hope to have them on sale before the end of the summer.

According to Barney Guarino, chief executive of Tempra Technology, the company that developed the can,

Science Correspondent Britain is likely to get the technology first. "We are talking to several major brewers, and we think we will have the cans on sale before the end of the year. "We expect to do one final test with consumers, then launch very soon after."

The more expensive beers and cocktails are likely to be the first to benefit from cooling cans, as - according to Mr Guarino - consumers are already used to paying higher prices for them.

"All the market research we have seen shows consumers don't mind paying premium prices for this," he claimed. "There simply aren't the economies of scale to make it cheap. But that will happen over time, and we hope these cans will become commonplace."

The system may also be developed for the hugely popular alcopop market.

However one brewer warned the technology could prove too expensive for the average consumer.

A spokesman for Scottish Courage, which brews beers including Foster's, Kronenbourg and John Smith's, said it would be unlikely to use the system at the present time. "The price premium is a problem, but this is an area we are looking at for the future," he said.