Photo by loop_oh/Flickr CC
Paul Wachter's interesting story about the strange twin pull dates for milk in New York City--one for the city, one for everyplace outside it--brings up a point beyond just how special we all know New York to be. Wachter wonders why the city hasn't changed a rule it began in 1959, which although modified still holds: milk sold in the city is marked with a sell-by date nine days after it is pasteurized, versus an average of 11 to 12 days in the rest of the country. He quotes milk producers who say that their own "stress tests" show that their milk lasts 15 to 21 days after pasteurization. New York dairy owners tell him that the shorter city shelf life has no basis in the facts they see on their delivery routes: the containers don't wait around longer on city streets than they do in supermarket parking lots before being transferred to refrigerators; the shorter pull date uselessly drives up production and shipping costs, and thus the price New Yorkers pay for milk. They and Wachter suggest that the city consider a rethinking of the rule on its 50th anniversary.
Still, Wachter admits that the milk he buys in New York does seem to go bad faster than the milk of his South Carolina childhood, and wonders whether the reason could be that city convenience stores don't observe the rule to store milk in refrigerated cases 45 degrees and under: many of those cases, as anyone in New York knows, are barely covered with clear plastic strips or are practically in the open.
I think Wachter answers his own question, though, when he contrasts his urban life today with his childhood:
When I was growing up in South Carolina, my family would buy milk by the gallon, which would keep for well over a week. Now, I buy milk by the quart and if it's good after four days I'm happy.
He uses less milk now than he did, and most people in cities do. Of course he buys milk less often and, by letting it hang around the fridge much longer than a family that goes through milk fast, gives milk a much stronger chance to go bad.
There's something else, too. The less milk you use at a time, the more air is left at the top--and air, along with heat, is the enemy of freshness. This "headroom" problem is familiar to me from my years of research for The Joy of Coffee. In the book I give the advice, followed by our own Jerry Baldwin, or progressively transferring coffee beans and ground coffee (NB, he doesn't approve of storing ground coffee, ever) to smaller and smaller containers and seal it tightly, to eliminate its exposure to oxygen. And I keep the containers opaque and at room temperature: never keep coffee in the refrigerator, and avoid the freezer unless you know you won't be able to buy fresh coffee within two weeks. Same goes for coffee in carafes--the more air not only the faster the coffee cools but the faster that oxygen can interact with the flavor-producing compounds in coffee.
The extension for Wachter, then, is to is to buy milk in the smallest quantity possible--the uneconomical solution favored by busy urbanites everywhere, especially ones facing five flights of stairs before they get to the front door. As with old pickles and chutney and mustard, though--to pick other common items in a desolate New Yorker's refrigerator--don't blame the product when they go bad. Blame the headroom! Or blame it first, at least. And let your gluttony or abstinence, Wachter's proposed solution to the problem, determine the size of the container of anything you buy fresh.