Raw (unpasteurized) milk

Raw milk is milk that has not been pasteurized to kill bacteria that could be harmful to humans. No matter how carefully it is produced, microorganisms (bacteria, bugs or germs) that can cause illness are often present in raw milk. These include Salmonella species, pathogenic E. coli, Staphylococcus aureus, Campylobacter jejuni and Listeria monocytogenes.

The illnesses these microorganisms cause range from mild discomfort, such as diarrhoea and vomiting, to life-threatening conditions such as listeriosis or haemolytic uraemic syndrome (HUS), which can lead to kidney failure even in otherwise healthy people.

How raw milk becomes contaminated#

Raw milk can become contaminated with microorganisms in a number of ways.

• Some bacteria may already be present in the milk if the animal has a disease, such as mastitis.
• Bacteria from the surface of the udder can contaminate milk during milking, or during any later handling or bottling.

Good hygienic practices during milking can reduce, but not eliminate, the risk of contamination. No matter what precautions a farmer takes, they cannot guarantee that their milk will always be free from harmful bacteria.

Sale of raw milk and raw milk products#

In many places, it is illegal to sell, deliver or provide raw milk for human consumption. Raw milk products are sometimes labelled as “cosmetic milk”, “bath milk” or “pet milk”. Where these products are allowed, they may be required to be treated to deter people from drinking them, for example by adding a bitter flavouring, and to be clearly labelled to alert customers that they are not for human consumption.

The production and sale of certain cheeses made from unpasteurized milk may be permitted, but only under strict controls over the production, transport and processing of the raw milk, to ensure the final product is safe for consumers. Businesses producing raw milk cheese, or transporting raw milk for cheese making, are closely regulated.

Who is most at risk#

Everyone is vulnerable to illness caused by organisms that may be present in raw milk. However, the risks are even greater for:

• young children
• elderly people
• people with underlying health problems
• people who have a compromised immune system
• pregnant women

Pasteurization and its effect on milk#

In many countries, pasteurization of cow’s milk has been required by law for many decades.

Pasteurization involves heating milk for a short period of time. Typically, milk is heated to 72°C (161.6°F) for 15 seconds. This process is very effective at destroying disease-causing bacteria that may be present in raw milk, making the final product safe to drink.

Pasteurization is a simple, straightforward process that produces milk that is safe and suitable for everyone. There is no substantiated evidence of any significant difference in the nutritional value of pasteurized and unpasteurized milk, and there is no credible scientific evidence that raw milk provides additional health benefits.

Key points#

• Raw milk is not pasteurized and often contains bacteria that can cause serious illness.
• Contamination can come from a sick animal or from the milking and handling process, and good hygiene cannot remove the risk entirely.
• Selling raw milk for human consumption is illegal in many places.
• Young children, elderly people, pregnant women and people with health problems or weakened immune systems are at greatest risk.
• Pasteurization makes milk safe to drink without reducing its nutritional value.

Where to get help#