Americans prefer chilled milk, while Europeans store their milk outside the refrigerator. The difference arises due to different taste/ flavor preferences of consumers and the pasteurization technologies used by dairy industry in these two geographies. Pasteurization, here means, heat-treatment process that destroys pathogenic microorganisms in certain foods and beverages.The treatment also destroys most of the microorganisms that cause spoilage and so prolongs the storage time of food.
In the U.S. and Canada, milk manufacturers use high-temperature short-time pasteurization, or HTST. HTST is efficient but results in milk that expires relatively quickly—usually within a week and requires storage in a refrigerator. That’s because the temperature used (about 161°F for 15 seconds) is enough to kill most bacteria, but some will proliferate if the milk hangs around long enough.
In Europe, another technique called ultra-heat-treated pasteurization, or UHT, is used. Milk is exposed to higher temperatures of 284°F for three seconds, decimating virtually all the bacteria and making it shelf-stable for a couple of months if left unopened. (Once opened, it has to be refrigerated.) Because it’s “cooked” at high heat and burns off some of the sugar, UHT milk also has a slightly different flavor.
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