Ever wondered why your New York milk has two expiration dates on it: the one for New York City, and the one for everywhere else? Paul Wachter at The Atlantic has the answer. According to the Health Department,
Milk shipped to the city is more likely to stand unrefrigerated for longer periods before it reaches stores and also during the trip from store to home. "In other parts of the country, the expiration date is often 11 or 12 days after the pasteurization, but our experience and research have shown that here, 9 days is a reasonable threshold," [the spokesman] said.
That said, milk producers dispute these claims. "The logistics of delivering milk in the city are not significantly different than in other areas of the state," Cyrus Schwartz of Elmhurst Dairy tells Wachter.