
12
Complete System Overview
BEER PROPERTIES
General Information
The object of every establishment serving draught
beer is to deliver the same high quality of beer to the
customer that is delivered to it by the beer distributor.
Unfortunately, this objective may be more difficult to
achieve than the vendor or proprietor realizes,
especially if he is not thoroughly familiar with the
relationships that exist between temperature,
pressure, and beer delivery systems, all of which have
a major effect on the quality of the beer delivered to
the customer. A brief discussion of these factors may
prove helpful in understanding why a problem exists
and what corrective action is required.
Beer is a unique liquid; no two barrels (even of the
same brand) are exactly alike. There are large
variations between brands. Chemically speaking, beer
is a “supersaturated” liquid. Simply stated, beer
contains excess carbon dioxide (CO
2
) which
dissipates or “out gasses” if allowed to stand in an
open container for a period of time. If this were to
happen, the beer would go “flat”. The presence of CO
2
gives beer its effervescent quality and distinct flavor.
There are several factors that affect the level of
carbonation, and therefore the quality and flavor of the
beer that is delivered to the customer.
Pressure
Beer is pressurized in the keg by the brewer to his
exact specifications, which are optimized for the best
possible flavor. For example, under pressurized beer
will taste flat and over pressurized beer will taste bitter.
It therefore follows that the vendor must carefully
balance his system to the beer specifications of the
brewer in order to dispense the beer with the best
possible flavor to his customers. Failure to do so can
result in poor tasting or foamy beer. This is why it is
strongly recommended that each keg or beer supply
be regulated by its own pressure regulator.
The optimum pressure for most domestic beer,
dispensed at normal temperatures and at sea level, is
12 to 14 pounds per square inch (psi) keg pressure.
STH13_Tech.book Page 12 Wednesday, September 15, 2010 3:20 PM