To make the topping, regular Ichiban beer is frozen to -5 degrees Celsius (23 degrees Fahrenheit) while air is continuously blown into it. It is kind of like when a child makes bubbles in their drink, except inside a blast freezer. Once the topping is placed onto regular, unfrozen beer though, it acts as an insulating lid and keeps the drink cold for 30 minutes. A side effect of this process is a creamier taste and texture for the beverage overall. In addition, it does not dilute the beer's flavor as it melts, the way ice would.
Kirin is currently previewing the Ichiban Shibori Frozen Draft in Tokyo, but plans to launch the drink in the rest of the country in May.
From the April 9, 2012, Prepared Foods’ Daily News