How do Dairy Producers make long life ultra-high-temperature milk?

Most of us wouldn’t consider drinking milk that has sat on the supermarket shelf unrefrigerated for some three months.

Then again, many people, especially those without small children, have never heard of ultra-high-temperature (UHT) milk.

Farm Best milk, made by Dairymen in Savannah, Georgia, is one of a number of long-shelf-life milks now available. You’ll find it not in the dairy section but probably along with boxes or cans of juice that are not refrigerated. How can it sit there so long without spoiling?

First, this milk is processed at 280 degrees Fahrenheit rather than at 170 degrees Fahrenheit, the normal temperature for pasteurizing milk. The high temperatures kill microorganisms that might escape unscathed by conventional processing. What you have, in fact, is sterile milk, totally free of any spores or bacteria that could multiply and cause the milk to spoil.

Secondly, the product is securely packaged to keep out air, light, and bacteria. After the milk has been purified by the UHT process, it is transferred to an aseptic packing machine which loads the milk into sterilized cartons.

These sturdy containers are made up of five layers of materials, three polyethylene, one paper, and one aluminum foil, and hermetically sealed. You can keep the cartons for months.

Once you open them, you should refrigerate the milk, but even then it won’t turn sour for about three weeks.