How to Pasteurize Milk

You'll need to learn how to pasteurize milk if you want to sell milk from dairy cows commercially. Some states do allow farmers to sell unpasteurized milk at their farms, and a few, including California, allow unpasteurized milk to be sold commercially; however, 23 states have full bans on the sale of unpasteurized milk. Be sure you know your state's laws before offering any milk for sale.

Why Pasteurize?
Milk is pasteurized to destroy most of the organisms that produce diseases in people. Pasteurization also limits fermentation. Pasteurized milk is heated to a certain temperature for a certain amount of time. The temerature (161 degrees Fahrenheit) kills the organisms. It does not kill slow-growing organisms or organisms that produce spores. To pasteurize milk at home, you will need a double boiler and clean, covered containers. There are several methods to pasteurize milk at home.

All utensils used in the process, including spoons and thermometers, must remain in the milk for the entire process. If they are removed and put back in, the milk becomes contaminated. Do not use a microwave to heat the milk, as the microwave has an uneven heating surface.

Method 1:
Heat the milk in a double boiler to 165 degrees Fahrenheit. Hold it at this temperature for 15 seconds. Cool the milk immediately to 145 degrees Fahrenheit by immersing the top of the double boiler in cool water. Constantly stir the milk. Add ice to the cooling water and continue to cool the milk to 40 degrees Fahrenheit. Store the milk in clean containers.

Method 2:
Heat the milk in a double boiler to 150 degrees Fahrenheit. Keep the milk at 150 degrees for 30 consecutive minutes. If the milk drops below 150 degrees, it must be heated again to 150 degrees for 30 consecutive minutes. Cool the milk as described in Method 1.

Method 3:
Put the milk in jars, then in a waterbath canner. The temerpature must stay at 150 degrees Fahrenheit for 30 consecutive minutes. Cool the milk to 40 degrees Fahrenheit as outlined in Method 1.