How does guinness widget work

18 thg 2, The purpose of the widget is to release the CO2 from some of the beer in the can to create the head. The widget is a plastic, nitrogen-filled. 13 thg 3, In bottles of Guinness with widgets, the device is more like a rocket, and is around three inches long. Brewers add pressurized nitrogen to the. 5 thg 3, The plastic devices called widgets blast the stout beer with nitrogen gas to aerate the head, making it taste as though it was just poured fresh.