Milk is a nutrition-packed food and a staple of many diets. Some even call it "nature's most perfect food".

In its raw state, however, milk can carry bacteria that can be harmful to humans.

Even the cleanest farm cannot ensure that raw milk is safe for you to drink. That is why all milk in Ontario, and the rest of Canada, must be pasteurized before it can be sold to consumers. It is the law, and it exists to protect you and your family.

What is pasteurization?

Pasteurization is a process that kills harmful bacteria that can make people sick. Some of these bacteria are Salmonella, E. coli O157:H7, Listeria and the bacteria that can cause tuberculosis.

Pasteurization works by heating milk to a specific temperature for a set period of time. The most common method of pasteurization in Ontario consists of raising milk temperature very rapidly to at least 72°C for not less than 16 seconds, followed by rapid cooling.

Since it was first used widely in the early 1900s, pasteurization has been credited with dramatically reducing illness and death caused by harmful bacteria in raw milk.

What's in pasteurized milk?

Pasteurized milk is an excellent source of:

  • calcium
  • protein
  • riboflavin
  • vitamin D (added to all types of milk at processing, to enhance calcium absorption)
  • vitamin A
  • phosphorous

It is also a good source of:

  • thiamine
  • vitamin B12

Pasteurization does not appreciably alter the nutritive value of milk.

High standards, strong regulation

Ontario has a rigorous dairy food safety system the purpose of which is safe, high quality milk and milk products, produced and sold by licensed dairy plants.

This is accomplished by the use of comprehensive regulations, farm and dairy plant inspection and laboratory testing.

Are there any antibiotics or artificial hormones in milk?

Veterinarians help farmers maintain healthy animals and may prescribe antibiotics if one is sick, just like your family doctor does when you get sick. When this happens, milk from the treated animal cannot be sold if it contains antibiotics.

The Ontario Ministry of Agriculture, Food and Rural Affairs has a program in place to conduct random testing of milk from every dairy producer once a month. This program routinely tests for antibiotics most commonly used in treatment of animal diseases and provides a high level of assurance that the milk is safe.

Farmers are penalized for antibiotic violations in their milk.

Fluid milk processors also test raw milk before allowing tank trucks to unload milk into the plants. Any milk found to contain antibiotics is rejected by the processor.

Growth hormones are not allowed to be used in dairy cows anywhere in Canada.

Does pasteurization cause lactose intolerance or protein allergies?

Pasteurization does not cause lactose intolerance or allergic reactions in people. If you are allergic or sensitive to lactose or milk proteins, you will have the same reaction whether you drink raw or pasteurized milk.

Dairy Jargon

Other than "pasteurized", there are many words used to describe different kinds of milk. Here are a few of them explained:

Certified organic milk
Certified organic milk comes from animals that are fed organically grown crops following a strict set of guidelines included in the National Standard for Organic Agriculture. All organic milk must be pasteurized before being sold.
Microfiltered milk
Has gone through a filtration process that increases the milk's shelf life. The process involves putting the milk through a very fine screen to remove most of the bacteria before it is pasteurized.
A process that reduces the size of fat particles in milk and distributes them evenly. This keeps the cream from floating to the top.
Raw or unpasteurized milk
Has not been pasteurized to kill harmful bacteria.