A controlled heat treatment that reduces harmful microorganisms in foods such as milk and juice to safe levels.
A controlled heat treatment that reduces harmful microorganisms in foods such as milk and juice to safe levels. Pasteurisation is a heat treatment designed to reduce the number of harmful microorganisms in a food to a level that is safe for consumers, without significantly changing the character of the food. It works by holding the food at a defined temperature for a defined time, a time-temperature combination validated to achieve a target reduction of relevant pathogens such as Salmonella, Listeria, E. coli and Campylobacter. Pasteurisation reduces pathogens but does not sterilise the food, so some spoilage organisms survive and pasteurised products still rely on refrigeration and date marking to stay safe. For dairy in Australia, pasteurisation is a mandatory processing requirement under the primary production and processing standard for dairy, and the sale of raw drinking milk for human consumption is not permitted. A dairy or juice processor must operate its pasteuriser to a validated time-temperature schedule and monitor it continuously, typically with recording thermometers and flow diversion that automatically returns under-processed product for re-treatment. Records of temperature and time are kept as evidence that each batch met its critical limits. For a food business buying in pasteurised ingredients, the practical task is to confirm the supplier is approved and the product is genuinely pasteurised, then to keep it cold and within its use-by date. Businesses should never substitute raw milk for pasteurised milk in recipes intended for vulnerable groups, and must not sell raw drinking milk. A regional dairy pasteurises milk by heating it to at least 72 degrees Celsius for a minimum of 15 seconds, records the temperature on a continuous chart, and relies on an automatic flow diversion valve to send any milk below the target temperature back through the process, keeping the batch records as proof the critical limit was met.
Frequently asked questions
Does pasteurisation make food sterile?
No. Pasteurisation reduces harmful microorganisms to safe levels but does not kill everything, so pasteurised foods still need refrigeration and date marking.
Is pasteurisation mandatory for milk in Australia?
Yes. Dairy processing in Australia requires pasteurisation or an equivalent validated process, and selling raw drinking milk for human consumption is not permitted.
What pathogens does pasteurisation target?
It is validated to reduce vegetative pathogens such as Salmonella, Listeria, pathogenic E. coli and Campylobacter to safe levels.
Why is pasteurised milk still kept cold?
Pasteurisation does not remove all spoilage organisms or bacterial spores, so refrigeration and a use-by date are still needed to keep the product safe.
How does a processor prove pasteurisation worked?
By operating to a validated time-temperature schedule, continuously monitoring and recording temperature, and using flow diversion so under-processed product is re-treated.
