Lesson 10 - Maturation and Finishing End of Unit SAQ
You have now completed the Maturation and Finishing Unit. This lesson enables you to test yourself on the material covered and to determine the level to which you have met the learning outcomes. It will provide you the opportunity to test your knowledge with a last set of self-assessment questions.
Suggested Response - Q3
**You have recently installed a beer recovery system, however, the micro-levels in the blended beer have spiked. You are under pressure to reduce your beer losses, so cannot simply stop beer recovery. What should you do to rectify the micro-infection issue?
Response:
Beer recovery systems are remedial processes to help reduce beer loss by recovering product entrained in yeast (from fermentation) or tank bottoms (from maturation). If a brewer is under pressure to reduce losses, then best practice during these processes will aid the reduction of yeast generation and volume of tank bottoms produced. This will yield a greater volume of the main transfer from the vessel to the next process stage.
One of the main risks of a recovery system, however, is an impact on beer quality. The following checks and measures should be taken to eliminate microbiological infection:
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All pipework and processes in the beer recovery system should be cleaned and sterilised at least once a day. The CIP regime should be reviewed to ensure cycle times, chemical concentrations and CIP validation are effective and if necessary, optimised.
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There must be a minimum residence time for maturation tank bottoms (feedstock) and recovered beer, to ensure microbiological stability and to reduce the risk of infection.
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Recovered beer should only be blended back on ‘positive release’ terms. This means taking a micro-sample of each tank of recovered beer and only blending back when laboratory results indicate the beer is microbiologically clean.
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If the problem persists, it may be necessary to include a flash pasteurisation step in the recovered beer process system; this will obtain a satisfactory beer quality for blending and avoids contaminating a ‘clean’ batch of beer. However, with the additional cost of the plant and utility requirements to run a pasteuriser, this should be a last resort whilst the source of the issue is being root caused.