PART II: QUALITY CONTROL IMPLEMENTATION
7. C OMPLAINT RECORDS
The last component providing support to a quality program is to record and monitor complaints. It was actively instructed to the whole Dois Corvos team to forward every complaint to the quality department in order to record the data. Weekly reviews of the summarized data help to get to the root of the problem and address concerns. One can also postulate that this information validates the rest of the quality program, as the lack of complaints might be related to an increase in beer quality.
Final remarks
The expected outcome of a quality program is to produce high quality products in a consistent manner. In a brewery, this translates into producing high quality beer every day. Beer quality can be defined by several parameters, as presence or absence of microbiological contamination, shelf life determination, sensory quality, and customer expectations. The goal of a quality program is to set criteria that define high quality beer in each parameter and create a system of policies, procedures, and specifications to meet the criteria. Starting a program with so many ambitions can be overwhelming, time consuming and has associated costs. Therefore, it is best to tackle one parameter at the time and work progressively towards the whole.
In the Dois Corvos quality program, the first approach was towards the reduction of microbiological contaminants. Microbiological testing provided information about the contamination of each batch, and was useful to determine whether the product should be commercialized or not. After implementing the testing that defined the presence or absence of microbiological contamination, the next step was to gradually implement tests that facilitate the tracing of the contamination source when one is present. For this purpose, several quality checks were distributed along the production line, starting with the wort stability test and validation of the tanks cleaning process, and finishing with the microbiological analysis of bottled beer and complaints recording. Nowadays, when a contamination is detected, one can easily look at the bulk of recorded data, make an assumption about the contamination source and focus on the resolution, instead of questioning the entire production line. This saves time and resources leading to an increase in the efficiency of the production.
The fitness of the fermentation was the second parameter to be tackled as it downgrading the sensory quality of the final product. The correction of the zinc concentration and the control of the yeast quality by viability monitoring contributed to the reduction of detectable off-flavors during the fermentation step.
Thus it is safe to affirm that both the consistent absence of contamination and fermentation-caused off-flavors led to an increase in the overall product quality, but it should also be noted that there is still space for improvement, as the work of a quality manager is never finished. Currently, it is being studied an approach to reduce the level of oxygen in packaged product as the current levels are excessively oxidizing the beer and speeding the beer aging process. This is causing a decrease in the product sensory quality during the shelf life, especially in hoppy beers.
In the near future, it is also being considered to acquire a centrifuge to reduce the solid residues in the packaged beer and reduce the overall processing time.
To finish this chapter, it is important to emphasize that quality control is essential to the brewing industry as it is for the food industry, and its importance should not be underestimated.
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Appendix a Graphic example of the viability analysis using flow cytometry from generation 0 to 4. Yeast cells were co-stained with SYTO9 (green fluorescence detected on FL1) and PI (red fluorescence detected on FL3). (A) Pseudocolor dotplots of side scatter (SSC) vs.
FL3; (B) Pseudocolor dotplots of FL3 vs. FL1
APPENDIX
A G r a
B G r a
Generation 0
Generation 1
Generation 2
Generation 3
Generation 4
58
Appendix b Graphic example of the viability analysis using flow cytometry form generation 0 to 4.. Yeast cells were co-stained with DIBAC4(3) ( green
fluorescence detected on FL1 and a red spectral shift detected on FL3). (A) Pseudocolor dotplots frontal scatter (FSC) vs. FL3;
(B)Pseudocolor dotplots of FL3 vs. FL1.
A G r a p
B G r a p Generation 0
Generation 1
Generation 2
Generation 3
Generation 4
Appendix c: CIP log used daily at the Dois Corvos production site.
Appendix d: Cellar log for fermentation monitoring used daily at the Dois Corvos production site