The electrical plate of the Guinness Surger unit generates ultrasonic waves that excite the nitrogen in the beer and create the surge-and-settle effect. Source: Diageo North America.

A maltier, more potent version of Guinness stout in bottles and cans helped mark the 250th anniversary or Arthur Guinness’s signing of a 9,000-year lease for the St. James Gate Brewery in Dublin, Ireland.