When you buy milk at the grocery store, do you hunt around for the jug that has the expiration date furthest in the future? Spoiled milk is certainly vile, but even if you took the milk that supposedly goes bad a week from now instead of two weeks, chances are it will be perfectly fine. Those "sell by" dates are completely arbitrary, and depending on where you live, once that date arrives, stores may be required to pour the milk down the drain.
That waste of perfectly good milk adds up, contributing to the 160 billion pounds of food waste in the United States every year and the 1.3 billion tons wasted globally. Researchers at the Harvard Food Law and Policy Clinic recently produced a short film called EXPIRED? Food Waste in America to highlight the problem and call for federal laws to standardize expiration dates across different types of food products with science-based dates.
EXPIRED? uses the particularly egregious example of Montana to highlight the milk waste problem. In Montana, milk must be removed from shelves and disposed of if it passes its "sell by" date, which is 12 days after pasteurization by state law.
The industry standard "sell by" date, which is an indicator of taste and quality, is 21 to 24 days after pasteurization. Pasteurization, by the way, kills harmful pathogens, meaning the milk is safe to drink even well beyond that roughly three-week period. The milk can't be donated to food pantries or shelters, and thousands of gallons are wasted each year in Montana.
You can blame the patchwork of confusing labeling laws that varies from state to state. Research shows that 90 percent of people consider "sell by" dates to be expiration dates. The issue is further muddled by the existence of "use by" and "best by" dates, which do indicate safety. You've probably encountered both sell-by and use-by dates on the same product no matter where you live—in one survey, 75 percent of yogurts in the UK had a "use by" date, while the rest had a "best before" date.
The UN has set its eyes on food waste, and food waste was a hot topic at the climate change summit in Paris last year. When you consider that nearly a third of the world's farmland is used to grow food that is never eaten, and which then ends up releasing 3.3 billion tons of greenhouse gas while sitting in in landfills, all while nearly 800 million people go hungry, you start to get a sense of the problem.
Some countries are striking out on their own. France recently passed a law that will require food past sell-by dates to be donated to food pantries. The USDA and EPA are aiming for a 50-percent reduction in food waste by 2030. Harvard's Food Law and Policy Clinic hope that clear and consistent labeling laws that distinguish between quality and safety will go some way to alleviating the problem. Two federal bills to standardize labels will be introduced in Congress later this month.
In the meantime, if you really want to know if milk is still good, you can use the time-tested sniff test, or let your taste buds decide. Good luck.