So long as there is no outward sign of spoilage (such as bulging or rust), or visible spoilage when you open it (such as cloudiness, moldiness or rotten smells), your canned fruits, vegetables and meats will remain as delicious and palatable as the day you bought them for years (or in the case of, say, Vienna sausages at least as good as they were to begin with). The little button on the top of jarred goods, which will bulge if there has been significant bacterial action inside the jar, is still the best way to tell if the contents are going to be all right to eat. Depending on storage, that could be a year or a decade. Similarly, cans of soda will keep their fizz for years, glass bottles for up to a year and plastic bottles for a few months. (Most plastics are gas-permeable.)
Oils, even rancidity-prone unrefined oils, stored in sealed cans are nearly indestructible as well (as evidenced by the two-gallon tin of roasted sesame oil that I’ve been working through since 2006). Oils in sealed glass bottles, less so. Oil in open containers can vary greatly in shelf life, but all will last longer if you don’t keep them near or above your stovetop, where heat can get to them.
How do you tell if your oil is good? The same way you would with most foods: Follow your nose. Old oil will start to develop metallic, soapy or in some cases — such as with canola oil — fishy smells. Don’t trust your nose? Put a drop on your fingertip and squeeze it. Rancid oil will feel tacky as opposed to slick.
Also from the oil-and-vinegar aisle: Salad dressings will last for months or over a year in the fridge, especially if they come in bottles with narrow squeeze openings (as opposed to open-mouthed jars).
Mustard lasts forever. Ketchup will start to turn color before the year is out, but will still remain palatable. Contrary to popular belief, mayonnaise — especially when it doesn’t contain ingredients like fresh lemon juice or garlic — has an exceptionally long shelf life. (High concentrations of fat, salt and acid are all enemies of bacteria and mold.)
The international aisle is a den of long-lasting sauces, pickles and condiments. I’ve yet to find the quality inflection point for oyster sauce, pickled chiles, chile sauces (like sambal oelek or Sriracha), fermented bean sauces (like hoisin or Sichuan broad-bean chile paste) or fish sauce. Soy sauce has a reputation for longevity, but I keep mine in the refrigerator to fend off the fishy aromas that can start to develop after a few months in the pantry.
We all know what a rotten egg smells like, right? Why else would it be a benchmark for describing so many other bad smells? But how many times have you actually smelled one: Once? Twice? Never? Probably never, at least according to the impromptu poll I conducted on Twitter. That’s because it takes a long time for eggs to go bad.