Brewery Biofilms
You don’t have to look far to find academic papers on biofilms in brewery operations.
But can your brewery afford high technology approaches to simply identify the organisms growing
inside the pipes? Your resources may be better spent on techniques that give you direct
data on how best to clean those lines.
Here, fouling cells were installed in a brewery for two months, in locations ranging from the
wort line down to bottling. With fouling cells, fluorescence microscopy found biofilms in three
segments of this process. FTIR data discovered that the biofilms were comprised of protein.
This protein resisted weekly caustic cleaning and hot water flushes.
With this approach, the brewery can explore new cleaning chemicals from their cleaning chemicals
vendor, and work to reduce the protein peak in the infrared spectrum as well as the visible
(but uncultivable) organisms under the microscope.
Brewery Wort Line Fouling:
Wort Line
At 2 months of exposure, the wort line fouling cell showed evidence of isolated clusters of bacteria
embedded in exopolymer or “slime.” The infrared spectrum of the two month fouling indicated protein
and ester components, and was resistant to the weekly caustic CIP process. The ester band was unique
to the wort line biofilm.
Brewery Fermentation Line Fouling:
Fermentation Line
The material observed in the fermentation line may or may not be a biofilm. The fouling looked the
same at 2 weeks as it did at 8 weeks by both microscopy and FTIR, indicating that the fouling reached
steady state by two weeks. There was no clear evidence for
bacterial cells, yet FTIR data indicated that the very thick fouling film in the fermentation line
was principally protein. The thickness of this layer indicated a problem with a sub-optimized water flush.
It is imperative to get the most out of your water flush before moving to chemical cleaning. Caustic
cleaning is less effective on thick fouling layers.
Brewery Bottling Line Fouling:
Bottling Line
At two weeks of exposure, the fouling cell in the bottling line showed a thin layer of protein and
nothing of note by fluorescence microscopy. By eight weeks of exposure, the protein peak had doubled in
the infrared spectrum and clusters of rod-shaped organisms had begun to appear. These early colonizing
bacteria were resistant to weekly caustic CIP treatment. These organisms were undetectable by the
brewery's standard microbiology techniques, including ATP.
