There’s nothing better to wash down some fresh cookies than a cold glass of milk--or at least that’s what Americans think. There are very few people across the country who store their milk outside of their fridge. In Europe, cold milk is virtually nonexistent. So what’s the deal?
Essentially, it all comes down to different methods of pasteurization. In North America, dairy manufacturers use high-temperature short-time pasteurization of HTST. It is able to kill bacteria in large batches, but milk will expire about seven to ten days after it is opened. It expires so quickly because it is exposed to roughly 161 degrees Fahrenheit for 15 seconds. Bacteria can proliferate if the milk hangs around too long.
In Europe and other parts of the world, a different method of pasteurization called ultra-heat treated pasteurization is used. During UHT, milk is exposed to 284 degrees Fahrenheit for three seconds. This kills virtually all bacteria and makes it shelf-stable for up to six months if unopened. Because it is treated at higher temperatures, it burns off some of the sugar, giving the milk a slightly different taste.
Pasteurization was a technique developed in the 1860s by French scientist Louis Pasteur. He realized that heating beer could kill bacteria. A few decades later, German agricultural chemist Franz von Soxhlet applied the principle of high heat to milk. Because dairy products were known to have contaminants that could cause life-threatening diseases like diphtheria or tuberculosis, HTST and UHT were developed and Europe favored the UHT method which would allow milk to last longer.
Not for lack of trying, American companies have tried to get consumers to warm up to the idea of buying shelf-stable milk, including a Parmalat campaign with Luciano Pavarotti in the early 90s. It simply may be too late to change tracks with American consumers.