Milk & Dairy – Pasteurization by Elizabeth Blessing
Pasteurization is a process of heating a food, usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food.
The process of pasteurization is applied to most milk today. Three types of pasteurization processes are practiced in the U.S.
Traditional pasteurization heats the milk to at least 165°F for 15 seconds. This is commonly referred to as “High Temperature, Short Time,” or HTST pasteurization, which is used by dairies like Trader’s Point Creamery and Snowville Creamery. Heating the milk removes 99.9 percent of the bacteria, which gives HTST milk a printed shelf life of 16-21 days from the date it was packaged.
Ultra pasteurization—the most widely used pasteurization process in Europe and throughout the world—is a more recently developed process. The process is often referred to as “Ultra High Temperature,” or UHT pasteurization. The UHT process heats the milk to 280°F for only two seconds and eliminates a larger percentage of bacteria than HTST pasteurization. When coupled with sterile packaging, ultra pasteurized milk has a shelf life of 70 days from the date of processing.
Low-temperature vat pasteurization is a less conventional (but US FDA-legal) alternative that heats milk at 145°F for 30 minutes and then quickly cools it. This retains a high percentage of the milk’s natural enzymes and bacteria, which add to the flavor and is also believed by consumers to add to the health benefits of the milk. It lasts about as long in your refrigerator as HTST milk. Many people are turning to vat pasteurized as an alternative to unpasteurized milk which can be difficult to get in some areas.
Most producers utilize a standard high-temperature pasteurization technique that also destroys enzymes in the process. Without them, milk is very difficult to digest. Many people who have been told they are lactose-intolerant can drink low-temperature vat pasteurized milk, like Green BEAN Delivery’s offering of Hartzler’s, without any problems. This is because Hartzler’s contains the digestive enzyme lactase. Without lactase to help break down the milk sugar lactose, the human body cannot assimilate the milk sugar.