Guinness and Boddingtons Pub Ale have had this for a while(9-10 years), with a round plastic “widget” (I cut a can open one time to find out). I always wondered how it worked.
Ironically the next video in the queue was also the Left Hand Nitro in a bottle, demonstrating the “hard pour” to get the nitro cascade effect and the bottles don’t use the widget, so I wonder if they’re already moving away from that technology. I think several people now have debuted nitro cans and bottles without the widget.
The widget is nothing more than a plastic container with a small hole, and it goes into the can empty. After filling and seaming, beer seeps into the widget. When you open the can pressure tries to equalize, but the higher pressure gas and beer can’t get through the small hole in the widget easily, so it squirts out as a stream and the agitation encourages foaming. So a hard pour does in fact do exactly the same thing, but without the Rube Goldberg quality or job security for patent lawyers.
A brewery I was working for was throwing the idea of cold brew coffee canned on nitro. The mobile canning company we were working with had a device that dropped a measured amount of liquid nitrogen in the can right before seaming. The theory was that the nitrogen would then work through the coffee and would pour with the Nitro effect.
We never did go this direction but it is a super cool concept.
Modern Times cans their cold brew coffee. I don’t know for sure if it’s nitro or not, but I think it might be. The cold brew coffee you can buy on draft at their pub is nitro, which makes more sense for coffee than CO2.