From KRISTIN WARTMAN
See also [the real answer for milk needs: local, raw milk]: Michael Foley: The Great Raw Milk Brouhaha — Four Easy Pieces ~DS]
Milk is truly one of the oldest, simplest whole foods – and we certainly drink a lot of it. According to the USDA, Americans consumed an average of 1.8 cups of dairy per person, per day in 2005.
But is the milk Americans are drinking today the same milk our ancestors drank thousands of years ago? Is it even the same milk our great-grandparents were drinking a hundred years ago? By and large, the answer is no.
Like many other modern foods, most of the milk sold today has been altered, stripped, and reconstituted. Once minimally processed, milk now undergoes a complicated and energy-intensive process before it ends up bottled and shipped to grocery store shelves. There are so many additives and processes involved that buying a gallon of milk or a cup of yogurt at your grocery store essentially guarantees that you’ll get a mixture of substances from all over the country — and possibly the world. But that’s not where it ends; milk by-products also now appear in a wide variety of other processed foods.
Lloyd Metzger, director of the Midwest Dairy Foods Research Center and Alfred Chair of the Dairy Department at South Dakota State, outlined the process: Milk is received at the processing facilities and is tested for off-flavors