Can you eat that 7-year-old can of soup?

Here's the funny but useful food story of the week: With the help of a food-safety expert, Chicago Tribune writer Julie Deardorff went through the old stuff in her pantry and figured out what to trash and what to keep.

Example: An undated box of dried mashed potato flakes, purchased in 2001 and taken along when its owner moved from Washington, D.C., to Chicagoland. (Why anyone would transport a box of potato flakes is not explained.)

The expert's opinion, as relayed by Julie: "The flakes are too dry to support the growth of microorganisms. No sign of bugs. Try it."

This little project started with a discussion about a seven-year-old can of Campbell's vegetable soup. As long as the soup can isn't rusty, damaged, dented or leaking, the contents are probably OK.

Alert: This post is not about refrigerated items. Also, stamping "best by" or "use by" dates on dried or canned foods generally is not mandatory -- and the date usually indicates quality, not safety -- but there are exceptions.

Other old items in Julie's pantry were also deemed worth trying by Martin Cole, director of the National Center for Food Safety and Technology at the Illinois Institute of Technology. Among them:

• An undated jar of peach salsa. Worth trying if you hear a "click" when you open the jar, and it smells like it's supposed to.
• A "best by May 18, 2007" can of tuna in water. "Canned foods that have been sterilized with heat -- which destroys enzymes -- are some of the safest products to keep," Julie says.

Here's a de-cluttering project for the weekend: Read Julie's column and check out the federal food-safety Web site to learn more about how to tell what's probably still good and what's not. The rules vary depending on the content -- for instance, high acidity vs. low acidity in canned goods can make a difference. Then go through all that old nonperishable stuff in your pantry.

If you come across something that's moldy, toss it out. Don't just cut out the mold. Cole said, "Don't scrape the mold off and eat the food. Mold can produce mycotoxins."

Related reading:

• When it's time to toss it
• The emergency fund you can eat

Published March 30, 2009