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发帖数: 1998 | 1 Walk into a grocery store in the United States or Canada and ask where you c
an find the milk, and you'll be directed to the refrigerated section. Ask th
e same thing in a grocery store in Europe, and you'll be directed to a regul
ar old room-temperature beverage aisle. Milk is perishable wherever you go,
so how can one part of the world keep theirs tepid while another takes pains
to keep it cold?
I Heat Up, I Can't Cool Down
The answer comes down to the way the milk is processed. Most milk is pasteur
ized, which means it's heated to a temperature high enough to kill illness-c
ausing bacteria. In the 1920s, a UK company developed a way to pasteurize mi
lk continuously, instead of in individual batches, for a cheaper and more ef
ficient process than the ones used previously. High-temperature short-time p
asteurization, or HTST, is what the U.S. and Canada (bagged milk notwithstan
ding) still use today.
But in the 1960s, the packaging company Tetra-Pak came up with a new techniq
ue. Ultra-high-temperature or ultra-heat-treated pasteurization (UHT) heats
the milk to an even higher temperature than HTST. The result is milk that st
ays fresh and shelf-stable outside of the fridge for about three months — w
ay beyond the seven-to-ten refrigerated days of HTST. That's what the majori
ty of the world uses, and why you can find milk out on the shelves in many c
ountries.
Don't Cry Over Warm Milk
Milk you don't have to refrigerate that won't expire for months — who doesn
't like that? Americans, that's who. The Italian company Parmalat tried sell
ing UHT milk on American shelves in the early 1990s and failed magnificently
.
For one thing, the high temperatures make UHT milk taste a bit more "cooked"
than HTST milk. But by and large, the failure was probably cultural. Americ
ans refrigerate a lot of things other countries don't — bread, butter, even
eggs. The U.S. puts more ice in their beverages and drinks their beer and w
hite wine colder. So is it any wonder that an offer of lukewarm milk got a h
ard pass?
Still, times are a'changing. With the U.S. gobbling up a quarter of the worl
d's energy production, maybe the country could use less refrigeration. Lucki
ly, with the rising popularity of other shelf-stable milks like soy milk and
almond milk, Americans are getting more comfortable with buying their milk
off the shelf. Walk into an American grocery store today, and you'll find si
ngle-serving milks sold at room-temperature from the likes of Horizon Organi
c and Fairlife. The revolution is coming, and it is unrefrigerated. |
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