How to Process Raw Milk at Home

The protein, fat, lactose, vitamins and minerals in milk make it one of nature's most nutritionally complete foods. Though most of the bacteria in milk from a healthy cow are harmless or beneficial, the risk of ingesting harmful bacteria such as E. Coli or salmonella are good reasons to pasteurize milk. The pasteurization process destroys potentially harmful bacteria in the milk and extends its shelf life. Always start with fresh milk since processing will not improve the freshness or flavor of milk.

Things You'll Need

• Raw milk
• Stove
• Double boiler
• Accurate metal or protected glass thermometer
• Stirring device
• Ice cubes

Instructions

1. Thoroughly wash the double boiler, stirring device, and thermometer you will use for pasteurization. Allow these items to air dry before use.

2. Prepare an ice bath of half water and half ice in the kitchen sink.

3. Add water to the bottom portion of the double boiler and bring the water to a boil. Add milk to the top of the double boiler. Heat the milk to a temperature of 165 degrees, stirring frequently. Maintain the temperature at 165 while stirring the milk constantly for 15 seconds.

4. Remove the double boiler from the heat and place the top of the double boiler with the hot milk into the prepared ice bath. Stir occasionally while you allow the milk to cool, taking care to avoid getting any water into the milk. Add more ice as needed until the milk reaches a temperature of 40 degrees. Cool the milk within four hours.

5. Pour the cooled milk into clean containers, cover them, and store in the refrigerator at a temperature below 40 degrees.

Tips & Warnings

• Keep the stirring device and the thermometer in the milk during the whole process to avoid the need to sanitize them before putting them back in the milk.

• Pasteurize up to a gallon of milk at a time, advises South Dakota State University.

• Heating above 165 is unnecessary for ensuring pasteurization. If milk is heated to 175 degrees, it will have a slightly cooked flavor. If heated higher than that, the cooked flavor will be more pronounced.

• Using the microwave for pasteurization is not recommended because of the uneven nature of microwave heating.

• If you need to pasteurize milk frequently, you may wish to consider purchasing a home pasteurization machine.

References

• Michigan State University
• South Dakota State University

Resources

• University of Minnesota Extension: Raw Milk Vs. Pasteurization Debate