Milk pasteurization is a process that heats milk to kill harmful bacteria, making it safe for consumption. Here's a breakdown of how it's done:
The Pasteurization Process
At most milk processing plants, the pasteurization process involves the following steps:
- Heating: Chilled raw milk is passed between heated stainless-steel plates.
- Temperature Rise: The milk is heated until it reaches a temperature of 161 degrees Fahrenheit (71.7 degrees Celsius).
- Holding Time: It is held at that temperature for a minimum of 15 seconds.
- Cooling: The milk is then rapidly cooled back down to its original temperature of 39 degrees Fahrenheit (3.9 degrees Celsius).
This method of pasteurization is known as High-Temperature Short-Time (HTST) pasteurization and is the most common method used today. This process effectively kills harmful bacteria, such as Salmonella and E. coli, which can cause foodborne illnesses.
Why Pasteurization is Important
Pasteurization ensures the following:
- Safety: Destroys harmful bacteria, making milk safe to drink.
- Increased Shelf Life: Extends the time milk can be stored before spoiling.
Summary of the Pasteurization Process
| Step | Temperature | Duration |
|---|---|---|
| Heating | Until 161°F (71.7°C) | Ongoing |
| Holding | 161°F (71.7°C) | At least 15 seconds |
| Cooling | Back to 39°F (3.9°C) | Rapidly |
This controlled heating and cooling process helps to maintain the milk’s nutritional value and flavor while ensuring it is safe to drink.
