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Safely pasteurize raw milk and other liquids
Learn about the heat-treating process of pasteurization, crucial for eliminating harmful bacteria from raw beverages like milk and cider. Discover easy methods using a double boiler or saucepan, reaching temperatures between 150 to 167°F (66 to 75°C). Let us guide you through the process for your safe beverage enjoyment.
Key Points to Remember
- Pasteurize liquids such as milk or cider in a double boiler. Maintain a temperature of 162°F (72°C) for 15 seconds, or 150°F (66°C) for 30 minutes.
- Pasteurize milk directly by heating on the stovetop until it reaches 149 to 167°F (65 to 75°C). Then, promptly transfer to a sterilized container.
- Sterilize containers for pasteurized liquids by boiling them on the stove for 10 minutes.
Procedures
Utilizing a Double Boiler Setup
Begin by filling the bottom pan with approximately 2 inches (5.1 cm) of water. Set up your double boiler on the stove, ensuring the bottom pan is halfway filled with water.
- A double boiler comprises specially designed pans that fit snugly on a stovetop burner, preventing ingredients from scorching.
- If a double boiler isn't available, use a large stockpot and a smaller saucepan, metal, or thick glass bowl. The smaller vessel should fit atop the stockpot without touching the water.
Place the liquid to be pasteurized into the top pan of the double boiler. Position the smaller pan over the larger one and pour in the liquid, leaving some space (1 to 2 inches or 2.5 to 5.1 cm) to prevent overflow.
- The double boiler method is effective for pasteurizing various liquids like milk, juice, and cider.
As the water boils, stir the liquid in the top pan continuously. Use a spoon to agitate the contents over the boiling water, preventing overheating, burning, or curdling. Remove any skin that forms on the liquid's surface using a ladle or spoon.
Heat the liquid to 162°F (72°C) for 15 seconds to ensure pasteurization. Employ a thermometer to monitor the liquid's temperature, ensuring it's submerged about two-thirds into the liquid without touching the bottom or sides of the vessel.
- Alternatively: Pasteurize the food or liquid at 150°F (66°C) for 30 minutes for an alternative method. Though time-consuming, this approach minimizes the risk of overcooking. Submerge a thermometer two-thirds into the liquid without touching the vessel's bottom or sides, maintaining a temperature above 150°F (66°C) for at least 30 minutes.
Place the saucepan in a cold water bath to expedite cooling. Set it in the sink and fill with cold water, adding ice cubes for faster cooling. Let it remain in the cold water until the temperature of the liquid reaches 68°F (20°C) or lower.
- You can alternatively use a large basin, bowl, or pot for this step.
Transfer the cooled food or liquid into sterilized containers. Leave a 2-inch (5.1 cm) space at the top of each jar. Once filled, seal the jars with appropriate lids.
- Using a funnel or ladle can help minimize spills during this step.
Keep the pasteurized items refrigerated. Store pasteurized liquids in the refrigerator until ready for use. Pasteurized milk can remain fresh for up to 2 weeks, while juice or cider lasts about 1 week.
- The temperature of the food or liquid should drop below 40°F (4°C) within the first 6 hours.
Utilizing Direct Heat
Warm the liquid on the stove until it reaches 149 to 167°F (65 to 75°C). Pour the liquid into a saucepan and heat it, stirring continuously. Insert a thermometer to monitor the temperature. Once it reaches the desired range, transfer it to a sterilized container. Aim to consume pasteurized milk within 2 weeks, or within 1 week for cider.
- Note: While the direct heat method has been proven effective for pasteurizing milk in certain studies, it's primarily recommended for milk and may not be suitable for other fluids or foods.
Guide to Sterilizing Bottles/Containers
Arrange glass containers in a large stockpot. Carefully position containers and lids in a large stockpot for sterilization. Ensure they stand upright without touching.
- Ensure the pot accommodates all storage containers.
- Sterilizing jars in a dishwasher doesn't guarantee proper sterilization like boiling does.
Submerge containers in water, covering by 2 to 3 inches (5.1 to 7.6 cm). Add enough water to cover containers evenly. Place the stockpot on the stove once filled.
- Arrange containers before boiling to prevent glass breakage from rapid temperature changes.
Boil water for 10 minutes. Heat on high until boiling, then reduce to a low boil. Keep containers and covers submerged for 10 minutes after reaching a full boil.
- Add 1 extra minute of boiling per 1,000 feet (300 meters) above sea level.
- Containers may bump slightly during boiling but shouldn't cause damage if the boil is gentle.
Use tongs or a jar lifter to remove containers from water. Turn off the burner, then carefully lift containers and covers from the hot water using tongs or a canning jar lifter.
- Exercise caution when handling glass containers, as they are still fragile.
Allow the containers to air dry on your countertop. Avoid placing them in the refrigerator or freezer for quick cooling.
- Refrigerating or freezing hot containers may cause glass breakage.
- Containers don't need to cool to room temperature entirely; slightly warm containers are less prone to breaking during pasteurization.
Handy Tips
- Consume home-pasteurized food within a few days of processing to maintain its bacteria-free status.
