Reply #30: The nitrogen gas makes it creamy [View All]

From my on-line reading I learned that the secret of Guinness's creamy mouthfeel, as the taste experts somewhat indelicately put it, is a mix of nitrogen and carbon dioxide rather than pure CO2 as the bubblizing ingredient. Nitrogen bubbles are much smaller than CO2 bubbles, a mere 50 microns in diameter, and produce a nice smooth head. But nitrogen doesn't produce bubbles as spontaneously as CO2. At the corner tap they deal with this by using a special nozzle that aerates the stout
with nitrogen as it's poured. In packaged goods that's not possible, so for a long time they were stuck with pure carbon dioxide. But science marches on. Using brain cells that might have solved the third-world debt crisis, a couple engineering types invented a little plastic device, known in brewing circles as a "widget," that's placed in each can (not bottle) of Guinness Draught. When you pop the top and pour, the pressure in the can drops to ambient, stout squirts out of the widget, and nitrogen is liberated from solution and aerates the exiting beverage. Result: nitrogen microbubbles galore, same as if the pouring were done by your local barkeep.

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