Making milk safe to drink

Pasturisation is the process used to kill harmful bacteria and pathogens that could be in the milk you drink while at the same time preserving the flavour and nutrition, it also extends the shelf life of the milk. Here is some information on how pasteurisation and how it works.

When was pasteurisation invented?

Louis Pasteur (27 December 1822 – 28 September 1895) was a French pharmacist, microbiologist and chemist famous for his discoveries in the fields of fermentation, vaccination and pasteurisation which was named after him. His research led to remarkable breakthroughs in the understanding of the causes and prevention of many diseases and laid the foundations of public health and hygiene.

Louis Pasteur completed the first successful test on April 20th 1862, he discovered that wine treated with heat killed off many of the dangerous bacteria present in untreated wine. This process was soon applied to beer, eggs, juice and of course milk. The goal of pasteurisation is to reduce the number of potentially harmful bacteria such as listeria and salmonella in the raw milk to make it safe for consumption.

There are two types of pasteurisation processes: HTST (high temperature short time) pasteurisation and LTLT (low temperature long time) pasteurisation.

So does heating up the milk to kill bacteria and pathogens change the milk?

Pasteurisation does not alter the milk in a significant way but heat-sensitive vitamins like vitamins C and B may be slightly reduced in pasteurised milk. The essential nutrients like calcium, protein and vitamins A and D are preserved.

The shelf life of pasturised milk is longer than raw milk because the number of bacteria that would cause spoilage has been reduced by the process. Pasteurised milk can have a refrigerated shelf life of two to three weeks depending on packaging and temperature-controlled storage.

Raw milk V Pasteurised milk

Raw milk is of course more natural and may contain more antimicrobials and has many people who swear by the health benefits. However, the benefits may be outweighed by potential risks such as severe infections caused by harmful bacteria such as E. coli, Salmonella and Listeria.

Pasteurisation is an important food safety measure that helps protect consumers from foodborne illnesses associated with raw milk consumption. Overall, pasteurization is a critical step in ensuring the safety and quality of milk for human consumption. It allows consumers to enjoy the nutritional benefits of milk while minimising the risk of foodborne illness.