new device

After mushh reslearch, I figured it was the drop in pressure when the can was opened, presumably the capsule has a weak seal which holds when under pressure and breaks when the can contents become at atmospere.

I saw a documentary from the Guinness factory, "the widget" doesn't have any seal or anything, it is just a ball with a small hole

when the can is opened and can pressure drops the beer and gas inside the ball jets out of the small hole

-Lasse

There is no gas IN the ball.

When the can is crimped, a small about of gas is injected into the can. The ball being empty and at room pressure, the beer will be pushed into the ball.

The rest is as you stated: When the can is opened, the liquid will release its gas and now the interior of the ball will have a higher pressure liquid then the liquid surrounding it. The liquid inside the ball will squirt into the beer causing a foam to be generated.

hamilton

the gas is dissolved in the beer, there is beer in the ball so there is gas in the ball ;)

-Lasse

This one has two really tiny holes, one in that little recess on top and another one at the bottom of the slot on the side.

can it rotate?

-Lasse

No, it's a hat shape, open on the bottom, with the brim glued to the bottom of the can.

Wexford is tasty beer. Get some and see for yourself. In the name of Science.

I think others have already explained. The foam-forming thingamagic doesn't have to be loose, it was just more convenient in the old days to toss it in. When we had one of those management seminars one of the guys and I got bored and headed for the campus pub, ordered a Guinness, whipped out the swiss army knife and cut open the can to find out what this clattering foam thing is. The bartender stood there with his jaw dropped. "Nobody has ever done that, you guys must be engineers".

We also had some delicious homemade pizza yesterday evening, baked in a charcoal-fired Weber barbecue. For the cerveza we had one of these:

Ok, full confession, we had two.

This sounds like the first "dessert beer" :

Yikes, phtoei, I'd never drink that stuff. I really dislike flavored beer.

We had their seasonal Christmas Ale. The guy at the store said it could probably be left alone another year but should have reached its peak just about now. He was right.