MASTER FOOD PRESERVERS & SAFETY ADVISORS
WSU/Whatcom County Cooperative Extension
1000 N Forest Street, Suite 201, Bellingham WA 98225-5594
Phone: 360/676-6736
FAX: 360/738-2458

Frozen Canned Foods

During the last cold snap some of my canned foods froze in the camper. Are they OK to eat?

There are two critical questions to ask to determine if frozen canned goods are safe to eat. Is the seal intact or broken? If the seal is broken, has the food thawed?

To test the seal, push on the end of the can or metal lid on top of the jar. If the vacuum seal is intact the lid will not move when it is pressed down. Check the seams carefully on commercially canned foods that have been frozen to make sure there are no openings.

If the seal is intact, the food is safe to eat, even after it thaws. If the seal is broken and the food is frozen, either refrigerate the food and use it as soon as possible or keep it frozen until you plan to eat it.

If canned food has a broken seal and has thawed, the safest approach is to discard the food. The food may have been warm enough for bacteria or mold growth.

A can will often bulge when food is frozen in it. If a can is bulged--and still frozen--keep it frozen in the freezer until ready to use, then thaw in the refrigerator. A can that still bulges after thawing should be discarded.

Be careful even if the bulge disappears after thawing. Look for any obvious signs of spoilage.  Listen for the vacuum-release sound when opening the can. As an extra precaution with low acid food, boil the food 10 minutes before tasting.

Information developed by Carolyn Rude, Retired WSU Extension Faculty - Family Living
March 1997

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