Thermoduric bacteria are heat resistant bacteria that survive pasteurization and have significant implications on the quality, type of products and the shelf-life of products we produce.
Don Crowley Milk Quality Specialist, Teagasc Clonakilty, outlines why farmers need to reduce thermoduric bacteria in milk and shows how to do this by the washing of the milking parlour.
Washing routine
Crowley recommends paying close attention to the following when washing a parlour in order to limit the amount of thermoduric bacteria in the system.
The air purge system – “The two things to watch for the system are: firstly – Is it working? and secondly – Are there enough pulses during the wash cycle?”
“Your target is 12-15 pulses per wash cycle, in a 10-minute wash. It releases a vat of water down the milk line that then hits the receiving jar.”
Milk pump – “Turn off the milk pump during washing. The jar will flood and send the wash solution up through the pipes and into the sanitary trap. Then you can flick on the pump again to clear it but in doing that you have cleaned those pipes.”
Receiving jar – “When you’re washing, it’s very important that the receiving jar is no more than 1/3 full because, if the pump is not able to clear this properly and it’s ¾ full, you have approximately 40/50% of your total wash solution in the jar – which is doing nothing to wash the plant itself.”
Sanitary trap – “The sanitary trap is a very common area for failing on thermoduric bacteria. It should be washed with every wash cycle. There’s a clip on top that should be opened and a drain-pipe out of it.”
“When the receiving jar fills up, the excess milk goes into the sanitary jar and hits the ballcock to stop the milk going into the milk pump. If it is not cleaned properly, it is a very common area for thermoduric build up.”
Vacuum line – “Washing the vacuum line is very important. It should be done at every service and make sure the technicians do it. Thermoduric are spore formers and, when they form spores, they will travel through the air and contaminate the milk.”
