How is pasteurized milk different from raw milk?

Pasteurized milk is raw milk that has been heated to a specified temperature and time to kill pathogens that may be found in the raw milk. Pathogens are microorganism such as bacteria that make us sick. Raw milk can contain pathogens such as Campylobacter, E. coli O157:H7, Salmonella, Listeria and other bacteria. Raw milk includes milk from cows, goats, sheep and other dairy animals.

By law, all milk sold to the public must be pasteurized and packaged in a licensed dairy plant. Only vitamins A and D may be added to the milk, no other additives or preservatives can be legally added to milk. Vitamin A improves eyesight, helps you to see better at night or in dim light, and helps you to tell colours apart. Vitamin D helps your body absorb calcium and reduces the risk of osteoporosis.

What are the risks of drinking raw milk?

According to a US Centre for Disease Control and Prevention study, the rate of outbreaks caused by unpasteurized milk and products made from it was 150 times greater than outbreaks linked to pasteurized milk. Children and younger adults were found to be more affected by the illnesses. Raw milk may contain pathogens that can cause disease or illness.

Some people say they grew up drinking raw milk and never became sick from it. However, public health authorities know of many cases of people who became sick from drinking raw milk.

Mandatory pasteurization of milk has eliminated large outbreaks of milk borne disease in Canada. However outbreaks arising from raw milk still occur and remind us of the hazards of drinking raw milk.

Who is at risk of getting sick?

Anyone can get sick from pathogens that may be found in raw milk.

Infants, children, pregnant women, seniors, and people with certain chronic diseases are more vulnerable to infection and have higher risk of getting sick from drinking raw milk. Infants and children are at greatest risk because they usually drink a lot of milk.

What can you do to protect yourself and your family?

Only buy your milk products from your grocer or other commercial stores. Always check the label on the milk product for assurance that it is pasteurized. Milk that you buy must be pasteurized and packaged at a licensed dairy plant. Be cautious of raw milk from farm gate sales or from "cow shares" as it is not approved, inspected, or monitored by the government.

If you live in a rural area and cannot buy commercially pasteurized milk, you can reduce the risk from disease by following 5 easy steps for home pasteurization:

1. Clean and sanitize milk bottles

   Clean empty glass milk bottles and tops with warm dish soap. Rinse and inspect containers to ensure that all visible soil and soap residue has been removed. Next, sanitize bottles using either heat or chemical as follows:

   Heat method:

   Immerse the containers in hot water (77°C / 171°F or hotter) for at least 2 minutes. Remove with clean tongs and allow containers to drain, cool and air dry

   Chemical method (200 ppm no rinse sanitizing solution):

   Mix 15 mL (1 tablespoon) of household bleach into 4 litres (1 gallon) of water; or mix 5 mL (1 teaspoon) of household bleach into 1 litre (4 cups) of water. Allow the sanitizer to contact the surface or utensil for at least 1 minute before wiping off with a clean paper towel or allowing to air dry

   Use Public Health Ontario’s chlorine dilution calculator tool to make up the proper sanitizer strength based on the concentration of your bleach product www.publichealthontario.ca/en/health-topics/environmental-occupational-health/water-quality/chlorine-dilution-calculator

2. Pasteurize Milk in a Double Boiler

   Place the raw milk in the top part of a double boiler. Gradually raise the temperature of the milk to 74°C (165°F) or hotter, and keep it at this temperature for at least 15 seconds. Stir often to keep all the milk at the same temperature. Note: Overheating may cause milk flavour to change

3. Ensure temperature reaches 74°C

   Check the temperature of the milk often with a clean and sanitized food thermometer. Put the thermometer about two-thirds of the way into the milk; do not rest it on the side or the bottom of the container. If you find the temperature has fallen below 74°C (165°F), raise the temperature to 74°C (165°F) or hotter and start the 15 second timing over again

4. Cool the milk

   Cool the milk quickly by putting the top part of the double boiler in an ice water bath. Stir often to make it cool faster. Continue cooling until the milk is at 20°C (68°F) or colder

5. Bottle the milk

   Pour the cooled milk into the sanitized bottles. Promptly put them in a refrigerator to further cool the milk to 4°C (40°F) or colder

Under ideal conditions, home pasteurized milk can keep in the refrigerator for up to 2 weeks.

Note: Do not use a microwave oven to pasteurize milk at home due to uneven heating of the milk. Use the method described above.

For More Information

For more information on milk safety, contact BC Centre for Disease Control’s Food Safety Specialist at 604 707-2440, or visit www.bccdc.ca/health-info/prevention-public-health/dairy-safety

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