Expiration Dates

Not actually Erin.

Picture by KJ Photography

& is used with permission.

Lokidude talked about pantry rotation on Tuesday, and David Blackard frequently donates food near its expiration date to the local Food Pantry. But food is expensive, and a significant investment in food could result in a financial hit if you aren't able to rotate through it quickly enough. This brings us to the question, "Are foods which go past their expiration dates no longer edible or nutritious?"

The answer is a resounding NO. While you need to be mindful of spoilage and decay in fresh foods like fruit & vegetables, and of insect or rodent contamination of dry foods like sugar, flour, pasta, etc, anything which is designed for long-term storage in cans has a surprisingly long shelf life.

How long?  Over one hundred years.

Food Expiration Dates
Back in 1990, the magazine FDA Consumer published an article titled The Canning Process: Old Preservation Technique Goes Modern. In that article, writer Dale Blumenthal tells the following tale:

The steamboat Bertrand was heavily laden with provisions when it set out on the Missouri River in 1865, destined for the gold mining camps in Fort Benton, Mont. The boat snagged and swamped under the weight, sinking to the bottom of the river. It was found a century later, under 30 feet of silt a little north of Omaha, Neb.

Among the canned food items retrieved from the Bertrand in 1968 were brandied peaches, oysters, plum tomatoes, honey, and mixed vegetables. In 1974, chemists at the National Food Processors Association (NFPA) analyzed the products for bacterial contamination and nutrient value. Although the food had lost its fresh smell and appearance, the NFPA chemists detected no microbial growth and determined that the foods were as safe to eat as they had been when canned more than 100 years earlier.

The nutrient values varied depending upon the product and nutrient. NFPA chemists Janet Dudek and Edgar Elkins report that significant amounts of vitamins C and A were lost. But protein levels remained high, and all calcium values "were comparable to today's products."

NFPA chemists also analyzed a 40-year-old can of corn found in the basement of a home in California. Again, the canning process had kept the corn safe from contaminants and from much nutrient loss. In addition, Dudek says, the kernels looked and smelled like recently canned corn.

If foods canned in the 1860s were edible and nutritious 100 years later, then foods preserved with modern techniques can easily last that long, if not longer, so long as basic precautions are taken. The most important is to store your canned foods in cool, dry places away from direct sunlight. This doesn't need to be a basement or root cellar; the pantry of your air-conditioned come will do.

Do Not Eat From [X] If...

Metal Cans

• an obvious opening underneath the double seam on the top or bottom of the can 
• a can with bulging ends 
• a fracture in the double seam 
• a pinhole or puncture in the body of the can
• an unwelded portion of the side seam
• a leak from anywhere in the can 

Plastic Cans

• any opening or non-bonding in the seal
• a break in the plastic
• a fractured lid
• a swollen package

Paperboard Cans

• a patch in the seal where bonding or adhesive is missing
• a slash or slice in the package
• a leak in a corner of the package
• a swollen package

Glass Jars

• a pop-top that does not pop when opened (indicating loss of the vacuum)
• a damaged seal
• a crack in the glass of the jar

Flexible Pouches

• a break in the adhesive across the width of the seal
• a slash or break in the package
• a leak at a manufactured notch used for easy opening
• a swollen package

Drug Expiration Dates
In short, the expiration dates on most preserved foods follow the conventions of expiration dates on medicine in that they are not a hard limit of "food is good until this date" but rather a case of "We can only guarantee 100% nutrition / medicinal effectiveness up until this date, with a drop-off thereafter."

In fact, the U.S. Food and Drug Administration created the Shelf Life Extension Program as far back as 1986 and has saved the government hundreds of millions of dollars each year by testing stored drugs to see if their storage could be extended instead of being replaced. A 2006 study of 122 drugs past their expiration dates showed that two-thirds of them were stable, and therefore still effective, resulting in their expiration dates being extended  an average of four years.

Further,

Some [drugs] that failed to hold their potency include the common asthma inhalant albuterol, the topical rash spray diphenhydramine, and a local anesthetic made from lidocaine and epinephrine, the study said. But neither Cantrell nor Dr. Cathleen Clancy, associate medical director of National Capital Poison Center, a nonprofit organization affiliated with the George Washington University Medical Center, had heard of anyone being harmed by any expired drugs. Cantrell says there has been no recorded instance of such harm in medical literature.

More topically, EpiPens which were were two years past their expiration date were found to be at least 90% effective, and one pen which was 50 months (four years) past its expiration maintained 85% effectiveness!

In short, don't throw away your medicines or canned foods just because the calendar is past an arbitrary date. Inspect the containers, do some research, and find out if they really need replacement.

Further Reading

• Extending Shelf Life Just Makes Sense
• Extended Use Dates Provided by Pfizer to Assist with Emergency Syringe Shortages
• Stability Profiles of Expired Drugs
• Epinephrine Concentrations in EpiPens