Kirin Brewery Co. will begin test sales July 15 of a draft beer product contained in a self-cooling keg that does not need electricity or cooling devices.

The testing will be conducted at selected liquor stores in Tokyo through the end of this year ahead of a planned nationwide launch of the product in 2004, the beer maker said.

The keg, to be imported from Germany, will contain 5 liters of draft Kirin Ichiban Shibori. The suggested retail price of the product is 2,620 yen, but consumers will have to pay an additional 2,000 yen for the keg, which will be refunded when they return the container.

Kirin said the self-cooling functions of the container were developed by Zeo-Tech, a German company. The technology makes use of water's natural tendency to cool its surroundings when it evaporates in a low-pressure environment.

When the consumer presses a lever on the top of the container, water surrounding an inner container holding the beer will start to evaporate and turn into ice.

In about 90 minutes, the beer will reach a temperature between 6 and 8 degrees, which is appropriate for consumption, and will maintain that temperature for roughly 12 hours, according to Kirin.

The keg can be reused at least 130 times, the company said. It hopes to sell 500 units of the product during its test sales.