The Meaning Behind Food Expiration Dates, How Long Food Really Lasts

“Sell By,” “Expires On,” “Best By,” “Use By”: There are more than 10 different expiration date labels on food packaging. But, unless they’re producing infant formula, there isn’t even a federal or Utah state law requiring manufacturers to stamp their food with an expiration date.

“It’s up to the manufacturer to pick the phraseology for those types of expiration dates,” explained Travis Waller, who leads Regulatory Services for the Utah Department of Agriculture and Food.

Even though expiration dates are voluntary, Waller says many manufacturers will use them because they have an interest in making sure consumers buy a quality product.

“I think they (expiration dates) do matter. You have some commodities that are potentially hazardous. If there’s one bacteria in there, over time, that one bacteria will multiply slowly and produce enough toxins to make somebody sick,” Waller said.

Here’s how the U.S. Department of Agriculture defines the most popular terms: A “Best if Used By” or “Before” is the date the manufacturer says their food will taste its best. But, a “Use By” is the last day they’ll vouch food is at its peak quality. And, “Sell By” is the last day the store should have an item on the shelf.

“My consumers tend to be confused because we educate retailers on keeping people safe,” said Sara Fausett, a dietician with Intermountain Healthcare. “Consumers are kind of left to their own devices.”

Fausett said the expiration dates speak to the quality of a food, more than they do to its safety.

“Where items are very likely to rot, we don’t want you using the sniff test,” explained Fausett. “Half the time, you can’t even smell it when it is going to give you food poisoning. And that’s the problem. The sniff test doesn’t cover every type of food poisoning. It’s just isn’t good enough.”

The list of foods she won’t eat past the printed expiration date includes: milk, dairy, fish, produce, anything with eggs in it or anything with a cream base.

Since expiration dates center around quality, we looked to the USDA to find out how long foods are good before safety is an issue.

Both Fausett and Waller recommend consumers have a thermometer in their fridges, to ensure whatever food they’re storing is kept at the right temperature.

“Personally speaking, I keep my refrigerator set at 36 degrees,” said Waller. “We’re constantly opening and closing it so the cold air gets out. If I keep it at a lower temperature, it provides a good threshold to make sure I’m holding at 41 degrees.”

Waller also points out food can spoil quicker than the expiration date.

“It might come from the plant, be loaded on a truck, shipped to a warehouse where it sits on a dock, placed in a freezer, and then back to the dock, shipped out to the store… all those variations in temperature have an adverse effect on the quality,” he said.

Fausett recommends consumers organize food like grocery stores do: first-in-first-out.

“I put the food item in, it’s one of the first things I pull out so it’s not rotting in the back of the refrigerator,” explained Fausett. “Say you bought spinach on Monday, and instead of waiting to pull it out on Sunday because you bought a bag of romaine (lettuce) on Thursday, you’ll leave the romaine in the fridge and pull out the spinach first.”

The sooner you store your food at the right temperature, the safer.

“Don’t leave your groceries in your car for 30 minutes in your car because you’re chatting with your neighbor in the street, go unload them and then chat.”