Stout beer is a dark, creamy, often bitter ale that is consumed around the world. Guinness, a dry Irish stout, is the most widely known, but there are others that are popular.

The Guinness widget is a tiny, plastic ball inside beer cans. During canning, pressurized nitrogen is added to the brew, which trickles into a hole in the widget.

Guinness was the most purchased beer in Britain between November 2023 and last month, according to the consultancy, even as overall beer sales in the U.K. fell this summer and fall.

Guinness, once synonymous with old Irish pubs and old Irish men, is increasingly winning over younger, beer-bent Americans like Mr. Quinn. “It’s having a moment,” he said.