With the holidays a dimming memory and the new year well under way, it's a time when many Canadians get the itch to organize their homes -- and that often includes a good clean-out of the kitchen pantry and fridge.
The need to dispose of unrecognizable leftovers in plastic tubs, now masquerading as a penicillin grow-op, is a no-brainer. Ditto for anything with a well-past its best-before or consume-by date on the label.
But in the absence of such information, deciding what food items are still safe to eat and what should be chucked can be a confusing task.
Just how long have those half-filled bottles of salad dressing and jam been lining the back of the refrigerator shelves? And exactly when were those cans of soup, kidney beans and tomato paste, which somehow migrated to the rear of the cupboard, actually purchased?
"We always have this expression that's used in the food area, that 'When in doubt, throw it out,"' says Massimo Marcone, a food scientist at Ontario's University of Guelph.
"And that's what we tell people, that it's safer to be overly careful than to go the other way," says Marcone, noting that the amount of money saved isn't worth the risk of food poisoning.
Still, he says, there are a few rules of thumb that can help consumers gauge how long various food products are safe to eat.
Let's start with the refrigerator and the ubiquitous bottle of ketchup.
Because ketchup contains vinegar, which acts as a preservative, the product can maintain its quality after being opened for at least a couple of months, Marcone advises.
"It doesn't mean that you can't keep it longer ... it depends on how many times you're taking it out of (the fridge). The more you take it out - if you're taking it out every month and putting it on your table (versus) once a week, that makes a big difference in how long it's going to last."
Removing it from the fridge and letting it warm up to room temperature can lead to bacterial growth, he says.
Other condiments that contain vinegar, such as pickles and relish, should also maintain their quality for at least two months, says Marcone. "It's hard to give the exact time on it because it depends on the way it was handled."
Even though mayonnaise also contains vinegar, it must be refrigerated once opened and spend as little time as possible in room-temperature air, as the eggs it contains make a perfect breeding ground for bacteria.
Foods packed in oil, such as sun-dried tomatoes, can last a year because bacteria don't grow well in oil, Marcone says. But it's crucial that any foods be kept below the oil line.
Margarine, which is 80 per cent oil, can last four to five months in the fridge; butter lasts about four months refrigerated, although it may get an unpleasant-tasting surface oxidation, which Marcone says can be scraped off.
As for jams and jellies, the acidity of the fruit and the sugar content act as preservatives that should keep them edible for up to eight months.
In the pantry, unopened glass jars of jam will maintain their quality for 12 to 18 months, as long as they are kept away from the light, which can cause oxidation, Marcone cautions.
Other pantry items, such as canned foods, have varying shelf lives depending on the contents.
Eat Right Ontario, a service of the provincial government, suggests consumers practise the "first in, first out" rule when stocking their pantry, bringing previously purchased items to the front and putting recent purchases behind them.
While manufacturers generally recommend that canned goods be stored for no longer than one year for best quality, "tomato products, canned fruits and other high-acid foods should be used within 18 months," Eat Right Ontario advises on its website. "Low-acid foods (such as canned vegetables) have a shelf life of two to five years." (Some food-science groups say a maximum three years.)
Cans should be stored in a cool, dry place - away from hot-water pipes, the stove, home-heating sources and sunlight - and should be kept dry to prevent rusting, which causes cans to leak and food to spoil.
And any can that has been dented should be pitched.
"People have to be careful with cans that have been dinged because as soon as a can has been dinged, it puts stress on the seams, which can permit air or contamination to come in," warns Marcone.
"Really they can be quite dangerous."
As to the age of a canned product, that can be difficult to determine if it's been languishing in the back of a cupboard and the consumer doesn't remember how long ago it was purchased.
Most cans will be stamped with a coded packaging date that looks like a series of numbers and/or letters, but they differ from one company to another and should not be mistaken as best-before dates.
Some manufacturers stamp the lid with a code that includes the production date, and that can be interpreted by consumers, says the Food & Consumer Products of Canada (FCPC).
"The first digit, a letter, denotes the month the product was made - A is for January, B is for February, C is for March and so on," an statement from the group says. "The second digit, a number, denotes the year the product was made - 8 stands for 2008, 9 stands for 2009 and so on."
When in doubt, consumers are advised to call the manufacturer.
But Marcone believes producers could make life a lot easier if bottled and canned foods were dated.
"With regards to the labelling of this information on the products to assist the consumer in determining the shelf life of their product, they could do a whole lot more," he says, suggesting that if consumers pushed for that packaging addition, industry would "soon respond."
Government regulations do not require packaged-on or best-before dates on such foods, says Peter Travers, a program officer at the Canadian Food Inspection Agency in Ottawa.
Only foods that have a "durable life" of 90 days or less must have a best-before or consume-by date, including fresh meats, eggs and sole-source-nutrition products such as liquid meal-replacements or power bars, he says.
As for Ottawa requiring that food producers provide information for consumers on longer-life canned or bottled foods, Travers says he has seen only a couple of letters over the years asking: "How come we don't have some dating on cans?"
"We haven't really identified a strong need for it."
Consumers could adopt their own tracking system, Marcone suggests, by writing the date on the lid of an item indicating when it was purchased or opened and stored in the fridge.
