Overview

Milk is a nutrient-packed food and a staple of many diets. However, in its raw (unpasteurized) state, 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. These laws exist to protect you and your family.

Pasteurization

Pasteurization is a process that kills harmful bacteria that can make people sick, such as:

  • salmonella
  • E. coli O157:H7
  • listeria
  • other harmful pathogens

Pasteurization works by heating milk to a specific temperature for a set period of time. The most common method of pasteurization in Ontario is to raise the milk’s 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.

There are other processes that milk can go through before and after pasteurization to increase its quality, such as homogenization and microfiltration. Microfiltration is a process where milk has gone through a very fine filter before it is pasteurized to remove most bacterial cells and impurities, which increases its shelf life. Homogenization is a process after pasteurization that reduces the size of fat particles in milk and distributes them evenly. This keeps the cream from separating and floating to the top.

Nutritive value

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 (added to skim, 1% and 2% milk, to replace what was lost in the skimming process)
  • phosphorous

It is also a good source of:

  • thiamine
  • vitamin B12

Pasteurization does not significantly alter the nutritive value of milk.

Dairy regulations

Ontario has a rigorous dairy food safety system to support safe, high-quality milk and milk products that are produced and sold by licensed dairy plants.

This is accomplished through:

  • comprehensive regulations
  • farm and dairy plant inspection
  • laboratory testing

Antibiotics and artificial hormones

Veterinarians help farmers maintain healthy animals and may prescribe antibiotics if one is sick. Milk from the treated animal cannot be sold if it contains antibiotics.

The Ministry of Agriculture, Food and Agribusiness (OMAFA) has a program to conduct random, monthly testing of milk from every dairy producer. This program routinely tests for the antibiotics most commonly used to treat animal diseases and provides a high level of assurance that the milk is safe.

Farmers are penalized for antibiotic violations in their milk.

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

Lactose intolerance and 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.