Lesson 2 - Cleaning Systems and Control
This lesson explores the concepts of hygienic design and the Cleaning-in-Place (CIP) systems in the brewery. We examine the nature of soils, the chemicals used to remove them and how we can validate cleaning effectiveness. We also consider the optimisation of modern cleaning systems within the brewery.
Validation of Cleaning Effectiveness
A great deal of effort has been put into designing and implementing the best CIP systems for breweries. When everything is running smoothly, how do we then measure our effectiveness and success?
CIP operation
In automated CIP systems, a controller monitors the temperature, pressure, flow rate, and conductivity (strength) of the CIP solution. These are compared to target values and the process is adjusted accordingly. If it is not possible to achieve the target value the system will alarm. Where rotary jets are used, rotation sensors are also monitored by the control system.
As well as monitoring conductivity, operators undertake titrations to measure the strength of the detergent. The bicarbonate formed in the reaction between caustic and CO2 increases conductivity so it is important to check that conductivity reading is due to caustic and not to bicarbonate.
Operators take samples of rinse water and check for residual detergent by measuring pH or using a dye that reacts with the detergent. They also check for ATP using and ATP bioluminescence machine (covered in the Microorganism Detection and Control lesson). Operators also visually inspect equipment to ensure it looks clean.
Laboratory staff take samples of rinse water and swab equipment for microbiological analysis for bacteria and wild yeast.
Regular maintenance is also carried out on the CIP system including inspection and cleaning of strainers, spray devices and the calibration of conductivity, temperature, pressure and flow measuring instruments.