On Tue, 30 Sep 2014 21:49:34 +0100, Tim Watts
wrote:


Once it's stops hissing, crack the valve open *slowly* just in case
there's some left but it's managed to freeze itself shut (unlikely but
Mr Murphy will always be hanging around on these occasions).

Mr Murphy would prefer a 70%/30% Nitrogen Co2 mix.

Sounds intriguing - what's that do?

Nothing too interesting . Kegs of Guinness in Great Britain used to
have a separate compartment which supplied that gas mixture as it
helps in the forming the dense head when the liquid is forced through
some small holes in the tap nozzle.
Then Murphys Stout was imported which also required the same gas
mixture for the same reason. This used ordinary kegs so the premises
that sold it had to start stocking cylinders and be equipped with
regulators for the 70/30 mix .An unfortunate knock on effect from
that was once such supplies were in place the Marketing Men had
another Gimmick to promote something new and we got a rash of IMHO
undrinkable abominations of bitters dispensed the same way sold with
nitrogenated heads , Eg Boddingtons Keg, John Smiths Extra
Smooth,Worthington Creamflow etc. Then there was that strange hybrid
Caffreys which also used the mixture.
In a way these did some good in being so awful that they just about
pushed the shrinking keg bitter market into a state of terminal
decline and allowed decent cask beer from smaller producers to have a
resurgence .

G.Harman