Cleaning Compounds
Efficient cleaning can be attained only if
the proper cleaning compound is incorpo-
rated. Spray cleaning is most effective with
the incorporation of a properly blended
cleaner having specific cleaning properties
for the soil that exists. The cleaning com-
pound should be low-foaming because foam
reduces velocity during circulation and tends
to prevent contact of the solution with part
of the surface. The appropriate cleaning
compound will prevent “beerstone” forma-
tions. It should also be formulated to prevent
metal attack, and it must be easily rinsed to
avoid the uptake of objectionable flavors by
the beer. (Other information on cleaning
compound selection, application, and safety
during use is discussed in Chapter 9.)
Sanitizers
Sanitizers such as chlorine, iodine, or an
acid-anionic surfactant should be incorpo-
rated with the final rinse in fermenters, cold
wort lines, and coolers. Because water can
contain viable microorganisms exceeding
100/mL, it is possible to have a sterile surface
after cleaning but bacteria or yeasts
deposited on the equipment surface after the
final rinse. (Additional information related
to sanitizers and their application is given in
Chapter 10.)
Heat Pasteurization
Heat pasteurization is still the most com-
mon method for microbial control in bever-
age plants, such as those producing
packaged beer. Although the energy costs
are high, it is, nevertheless, a convenient
method. Alternative procedures have been
investigated because of energy costs and the
adverse effect of heat on the flavor of drinks
such as beer. Such alternative procedures,
frequently called cold pasteurization, include
the use of chemical compounds, such as
propyl gallate, as well as millipore filtration,
either followed by aseptic packaging or used
in conjunction with other chemical treat-
ments. It appears that the practice of cold
pasteurization will increase in the future.
Official approval of chemical compounds
is subject to change as new technology and
information related to safety become avail-
able. The bacterial count of pitching yeast
may be reduced by treatment with dilute
acids such as phosphoric, sulfuric, and tar-
taric acid. Acid treatment can reduce bacter-
ial infection, but it has an adverse effect on
the yeast culture, and retarded fermentations
can occur in the first few cycles after treat-
ment. Sulfur dioxide (SO 2 ) has been used in
the past for control of wort bacteria.Aseptic Filling
Aseptic filling is considered to be a non-
pasteurization process that involves ultrafil-
tration techniques to remove the spoilage
organisms from beer before packaging.
Because ultrafiltration occurs before packag-
ing, spoilage microorganisms can enter the
product. The comments that follow were
provided by Remus (1991b) to ensure deliv-
erance of a high level of sanitation in aseptic
packaging.Hygiene Practices
It is important to have closed filling rooms
with a positive pressure of filtered air. The
workers' apparel should always be clean, and
before workers enter a room, their hands
should be washed with a sanitizing soap. A
conveyor lubricant system that reduces
microorganisms should also be utilized.
The interior of the filler should be cleaned
and sanitized daily, utilizing re-circulating CIP
equipment. The exterior of the filler, convey-
ors, associated equipment, floors, and walls
should be foamed or gelled, then sanitized
daily. This process should provide a residual
antimicrobial activity because a detergent or