Cabin Pressure and Carbonated Beverages

An important factor that should be considered here is simply the material of the container. Bubble formation in a cup depends strongly on the type of cup used, since most bubbles will form at the interface between the fluid and the cup.

Interesting points, let me say also that the type of liquid is relavent also in my opinion. I went to check on my retirement property which is at 9,600 feet above sea level in central Colorado. My new neighbor there invited my wife and I over for drinks and I saw something fascinating. If a bottle or can of beer was opened and immediately poured, with the can upside down, into the glass, the beer foam would form and spill over the glass just like at sea level.

He then opened and poured a full can of Guiness dark Ale into a similar beer glass the same way. I thought the foam would form and spill over like the beer. The foam immediately dissolved, however, and turned back into beer. 2 inches of foam turned into 2 millimeters of foam in just 2 or 3 seconds. Very weird. The remaining foam was much denser also.

Originally posted by steve645
Interesting points, let me say also that the type of liquid is relavent also in my opinion. I went to check on my retirement property which is at 9,600 feet above sea level in central Colorado. My new neighbor there invited my wife and I over for drinks and I saw something fascinating. If a bottle or can of beer was opened and immediately poured, with the ...[text shortened]... illimeters of foam in just 2 or 3 seconds. Very weird. The remaining foam was much denser also.

Might it be because some Guinness cans contain some nitrogen and a 'widget?'

http://en.wikipedia.org/wiki/Widget_%28beer%29

Originally posted by JS357
Might it be because some Guinness cans contain some nitrogen and a 'widget?'

http://en.wikipedia.org/wiki/Widget_%28beer%29

Not entirely. Draught Guinness (and some other draught porters) also have that dense foam. It's a consequence of the way it's brewed and typical of the style, but I don't know the technical particulars. I do know that drawing a pint of porter is an art unlike that of drawing bitter, pilsener, or other more typical beers.

(But no, it's nothing to do with Colorado, in principle. The effect may be greater there, but it occurs at any height.)

Richard