How to Pasteurize Milk at Home

Most milk available in supermarkets is pasteurized milk, which means it has been heated to destroy any bacteria or harmful organisms. If you get raw milk straight out of a cow, you must pasteurize it to avoid health problems. The easiest method of home pasteurization uses a double boiler as described in the following steps.

Difficulty:

Moderately Easy

Instructions

Things You'll Need

• Glass milk bottles
• Raw milk
• Double boiler
• Metal-stem thermometer

1. Boil empty milk bottles submerged in water for 10 minutes to disinfect them. Alternatively, you can place the milk bottles in an oven preheated to 212 degrees F (100 degrees C) for 20 minutes to disinfect.

2. Pour raw milk into the top of a double boiler and fill the bottom section with water.

3. Place a metal-stem thermometer into the milk to monitor its temperature. Keep the thermometer from touching the sides or bottom of the double boiler so you get an accurate temperature reading of the milk, not the container.

4. Heat raw milk to 145 degrees F and keep it at that temperature for at least 30 minutes. Stir constantly to avoid burning and to maintain an even temperature. For a faster method, heat the milk to 165 degrees F for at least 15 seconds, stirring constantly.

5. Put the top section of the double boiler that holds the heated milk into a pan of cold or ice water to cool the milk. Continue to stir.

6. Cool the milk until it reaches 40 degrees F or below.

7. Pour the pasteurized milk into the disinfected milk bottles. Cover and store in the refrigerator.

Tips & Warnings

• You can keep pasteurized milk stored in the refrigerator for up to two weeks.