Message 14717 of 39188 in General Discussion

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> > Dammit Dan!  You have all the cool stuff......I wonder where I can 
> > 
> > order a "beer bidet"....LOLOLOL.  I have noticed that when my "frosty 
> > 
> > mugs" are a little too cold, that often my beer tends to foam more.  
> > 
> > Any corrolation here?  I can take a mug from the front of the cooler 
> > 
> > (the ones in back are much colder) and I don't tend to have much of a 
> > 
> > foaming problem. Hmmmmm...interesting.  I think I'll just experiment 
> > 
> > tonight and try dipping one of the frigid mugs to see if my theory is 
> > 
> > plausible (given that all other factors are correct, i.e. keg temps, 
> > 
> > line length, CO2 pressure, etc).
> > Time to start getting ready for the Friday night onslaught!
> > 
> > Devon
> 
> CO2 releases faster in a colder temperature. Try pouring coke in a 
> glass full of icecubes compared to an empty one.
> 
> //Petter

No... CO2 releases less in a colder temperature. That's why the beers foam 
more in summer and you need MORE pressure to let the beer keep it's natural 
dissolved CO2. It is an error which is made often. In a summer when the beer 
foams a lot, people reduce the pressure on the tap system. But this pressure 
should be raised. This pressure is needed to prevent the beer releasing it's 
naturally dissolved CO2. And to overcome the drag of the tubes. That's why the 
pressure shouldn't be to high too, because the beer would flow to fast in that 
case.

Foam from ice cubes can be explained with the theory about the tiny bubbles 
which dissolve back into the beer. Ice can act as a nucleation site where the 
bubbles don't have to start as microscopic spheres (compare with a lump of 
sugar which does the same and even better) but ice has also got "premade" 
bubbles and dissolved oxygen in it which "produces" bubbles when the ice 
starts to melt. You can see in a glass that places where bubbles form are 
surfaces of anything(icecubes, glass surface, sugar).