Food expiration dates are a surprisingly recent invention. Printed dates didn’t appear on most grocery store products until the 1970s, when consumer advocacy groups pushed for more transparency about food freshness. Before that, shoppers had to rely on their own senses, trust the grocer, or simply hope for the best.
The Earliest Date Stamps
One of the most popular origin stories traces date-stamped food back to the Capone family in the 1930s. According to a 2010 book by Al Capone’s grandniece, Deirdre Marie Capone, it was actually Al’s brother Ralph who first pushed for date stamps on milk bottles. Ralph Capone reportedly earned his nickname “Bottles” not from bootlegging but from this idea of printing dates on milk so grocery shoppers could judge freshness. Snopes has investigated this claim and found it difficult to verify independently, but the story has become deeply embedded in food history lore.
Whether or not the Capones deserve credit, the underlying problem was real. In the early twentieth century, milk spoilage was a genuine public health crisis, and there was no standardized way for consumers to know how old the milk on the shelf actually was. Some local governments began requiring date codes on dairy products in the 1930s and 1940s, but these were often coded systems meant for retailers, not shoppers. A string of numbers or letters on a bottle cap told the store when to pull the product, but an ordinary customer couldn’t decode it.
The 1970s: Open Dating Goes Mainstream
The real turning point came in the early 1970s. Consumer rights movements of that era demanded what the food industry called “open dating,” meaning dates printed in plain language that anyone could read. Before this, most packaged foods carried only closed codes, internal references that were meaningless to the average buyer. Grocery chains began voluntarily printing readable dates on perishable items like dairy, meat, and bread. By the mid-1970s, open dating had spread widely enough that Congress held hearings on whether to make it a federal requirement.
Several bills were introduced during the 93rd and 94th Congresses in 1973 through 1976, proposing mandatory open dating on perishable foods. None of them passed. Instead, the federal government left dating largely up to manufacturers and individual states, a patchwork system that persists today. Some states enacted their own dating requirements for specific products like milk or shellfish, while others imposed no rules at all.
What Federal Law Actually Requires
Here’s something that surprises most people: federal law does not require expiration dates on food. The single exception is infant formula, which must carry a “Use-By” date because its nutrient content degrades over time. For every other product in your grocery store, date labels are entirely voluntary. Manufacturers print them as quality guidelines, not safety deadlines.
The USDA distinguishes between several types of date labels, and none of them (except on infant formula) indicate safety:
- “Best if Used By/Before” refers to when the product will taste or perform at its best. It’s a quality suggestion, not a safety cutoff.
- “Sell-By” is directed at the store, telling staff when to rotate stock. It’s an inventory management tool.
- “Use-By” is the manufacturer’s recommendation for peak quality. On everything except infant formula, it’s still not a safety date.
- “Freeze-By” suggests when to freeze a product to preserve quality.
The distinction matters because millions of people treat these dates as hard safety limits, which they were never designed to be.
How Manufacturers Choose the Dates
There’s no universal formula for setting a “Best By” date. Each manufacturer determines its own dates using a combination of lab testing and sensory evaluation. The two standard approaches are real-time stability tests, where food is stored under normal conditions and checked periodically, and accelerated stability tests, where food is exposed to elevated temperatures or humidity to speed up degradation.
In accelerated testing, scientists use the relationship between temperature and the rate of chemical breakdown (described by the Arrhenius equation in chemistry) to predict how long a product will last under normal storage. They measure indicators like pH changes, microbial growth, nitrogen compounds that signal protein spoilage, and simple sensory checks for taste, smell, and texture. A product stored at 25°C might show decay in one day, while the same product at 12°C lasts seven days. Researchers use those data points to calculate a recommended shelf life for the temperature printed on the label.
Because companies set their own dates and tend to err on the conservative side to protect their brand reputation, many products remain perfectly safe well past their printed dates. The dates reflect when quality starts declining, not when food becomes dangerous.
The Food Waste Problem
That conservative approach has a significant downside. The USDA estimates that roughly 30 percent of the American food supply is wasted at the retail and consumer levels, and confusion over date labels is one of the primary drivers. Shoppers see a “Sell-By” date that has passed and throw out food that’s still safe to eat. Retailers pull products from shelves days before they actually deteriorate. The result, according to research highlighted by Ohio State University, is that label confusion contributes to over 30 percent of total food waste.
Efforts to fix the problem have focused on standardizing labels down to just two phrases: “Best if Used By” for quality and “Use By” for the rare cases where safety is genuinely time-sensitive. Versions of a Food Date Labeling Act have been introduced in Congress multiple times, most recently in 2025, though none have become law yet. Several major food industry groups have voluntarily adopted the two-label system in the meantime.
Smart Packaging and Real-Time Freshness
The fundamental limitation of a printed date is that it’s static. It assumes the food was stored perfectly from the factory to your kitchen, which rarely happens. A carton of milk left in a hot car for an hour ages far faster than one kept consistently cold, but the printed date can’t account for that.
Newer packaging technologies aim to solve this with time-temperature indicators, small labels embedded in packaging that change color based on the actual thermal history of the product. Other intelligent packaging systems use sensors that detect gases released during spoilage, giving a visual alert when food is genuinely degrading rather than when an arbitrary calendar date arrives. These technologies are still working through regulatory hurdles, including concerns about whether sensor materials might migrate into food, but they represent a fundamental shift from “this date was calculated in a lab six months ago” to “here’s what’s happening inside this package right now.”