Hmmm, good question. Looks like for the nitro can they're using a nitro widget, like canned Guinness uses. They're pretty controversial - were discussed to deat

Hmmm, good question. Looks like for the nitro can they're using a nitro widget, like canned Guinness uses. They're pretty controversial - were discussed to death when they first came out. I guess, hypothetically, when the can is opened you're releasing all the nitrogen at once, and it could result in a short-lived physical change. edit: I'm also seeing some reporting that some of Stumptown's products are pressurized with nitrous oxide, and may not be 100% coffee. (eg, have dairy or emulsifiers.)