Are canned goods that are frozen inside the jar safe to eat?
If home or commercially canned foods freeze, they are still safe to eat IF the seal (or seam of the can) is not broken.
When commercially canned foods freeze, the food
inside expands and the can may bulge or even burst.
Throw cans in this condition away, without tasting
(don't even give it to your dog). Even if the can is not
bulging, there may be microscopic openings in the seams
due to stress.
Thaw frozen canned goods slowly; a refrigerator is an
ideal place to thaw such foods. Commercially canned
foods can be placed on a tray or plate to check for
leakage from the seams that may not be apparent. If any
leakage occurs, discard the food.
Use canned goods that have frozen as soon as possible
(providing seals and seams are not leaking) as quality
will deteriorate quickly.
Starchy foods may curdle (separate) when frozen --
thawing and heating should correct this problem.
As an added precaution, boil all low acid foods 10 to
20 minutes, depending on the food, before tasting.
If produce canned at home was processed in jars made
for freezing as well as canning, the frozen jar may be
placed directly in the freezer and kept there until
used. Keep in mind that quality, especially texture,
will be affected. Therefore, this food should be used as
soon as possible.
Any food that looks or smells bad should be discarded
so that humans and animals cannot eat it.
To prevent loss of food, home and commercially canned goods should be stored in an area where they will not freeze. While an unheated porch or garage might be acceptable during a normal Missouri winter, these areas will not offer enough protection from freezing during the sub-zero temperatures that Missouri sometimes has. If jars must be stored where they may freeze, wrap them in newspapers, place them in boxes and cover them with more newspapers and heavy blankets.
Barbara Willenberg, Nutritional
Sciences, University of Missouri-Columbia
Last update: Tuesday, May 05, 2009