Is it still good? The shelf life of a ‘best before’ date on food

The common food dilemma of following ‘best before’ dates as ‘expiry’ dates likely contributes to 1.3 billion tons per year of waste. This represents more than 30 percent of the food produced and an estimated cost of $34 billion dollars in North America.

In most instances, best before dates have to do with food quality – freshness, texture, taste and colour – not safety. As long as the package is unopened, has been stored under proper conditions and for canned goods, the can is not bulging, food can be eaten past the ‘best before’ date.

The Canadian Food Inspection Agency (CFIA) lists requirements for date labelling on pre-packaged food. ‘Best before’ dates are required on all food products that keep fresh for less than 90 days, such as milk, along with required storage conditions, like ‘keep refrigerated’. They are not required on food products with a shelf life more than 90 days such as canned tomatoes and dry pasta.

There are no government regulations indicating what the dates should be or how they should be determined. “The manufacturer determines the date on the package based on the worst-case scenario,” says Keith Warriner, professor in the Department of Food Science at the University of Guelph. Warriner asked one company how it addressed the undertaking. He was told a product would be left at room temperature and assessed daily. When they thought the quality was unacceptable, they set a best before date. Warriner adds that at times, the best before date is chosen to fit the needs of the retailer without any formal shelf-life studies.

As most best before dates are estimates, there are a few exceptions. For deli meats, hot dogs and soft cheeses, best before dates are based on the length of time it takes the pathogen Listeria monocytogenes to grow. Some jarred ready-to-eat foods have a shelf life of 42 days, depending on the extent of heat treatment, says Warriner. Low acid foods such as soups and sous vide-type products do not receive sterilization treatment and are in danger of developing Clostridium botulinum or botulism. Warriner advises adhering to the best before date when it comes to these products even though they may look and taste fine. Jarred products such as pickles and salsa are low botulism risk. Unlike most bacteria, Listeria and botulism spores can multiply and spread in the refrigerator.

The following are refrigerated (4 degrees C/40 degrees F) products in which the shelf life is based on food safety.

Low-acid vegetable or fruit juices (pH of 4.6 or greater): 3 weeks

Pasteurized jarred soups: 7 days

Non-dried deli meats: 5-7 days

Sous vide (“under vacuum”) red meat, poultry, fish: 10 days maximum

‘Expiry’ dates are under a different classification. They are required on only a few items such as meal replacements, nutritional supplements and infant formulas. These products should not be consumed after the expiration date because the nutrient content stated on the label may have degraded. They should be discarded.

Fresh food packaged at the store must have a ‘packaged on’ plus a ‘best before’ date. This applies to foods like vegetables, cut-up fruit, meats, bread, muffins and cakes baked on site.