Frozen Cans
Cans frozen accidentally, such as those left in a car or basement in sub-zero temperatures, can present health problems. If the cans are merely swollen — and you are sure the swelling was caused by freezing — the cans may still be usable. Let the can thaw in the refrigerator before opening. If the product doesn't look and/or smell normal, throw it out. DO NOT TASTE IT! If the seams have rusted or burst, throw the cans out immediately, wrapping the burst can in plastic and disposing the food where no one, including animals can get it.

Food Safety of Frozen Canned Food
More than pipes can freeze during icy weather. Frozen canned foods stored in unheated storage area may cause concern. If canned foods have frozen, they may still be safe to eat. Safety will depend on the condition of the can or jar. To evaluate, consider the following:
Metal Cans
• If the seams are still intact, the food is safe to use. Thaw gradually and store at room temperature.
• If the seam has broken and the food has thawed out, it should be discarded.
• If the seam has broken and food is still cold (below 41F), it may be safely transfer to a container. Store in the refrigerator or refreeze for future use.
• For an extra margin of safety, all low acid foods (meats, fish, poultry and vegetables) must be discarded.
Glass Jars
• If jars have cracked or broken during freezing, discard
• If the seal is still intact, the food is safe to use. Thaw gradually and store at room temperature. Recheck seal once thawed.
• If the seal is broken and food is thawed, discard
• If the seal is broken and food is below 41F, it may be safely transferred to a container. Store in the refrigerator or refreeze for future use.
• All food that is frozen in glass jars should be examined for spoilage before use. All low acid foods (meats, poultry, fish, and vegetables) must be discarded.
General
• Discard any product with an off color or odor. DO NOT TASTE food that looks or smells suspicious. When in Doubt, Throw it Out.
For more information, please contact the Fairfax County Health Department 703-246-2444; TTY: 711.

The quality of black and green tea tends to improve. When stored at subzero temperatures, tea leaves become covered with tiny cracks. This makes tea more aromatic and delicious. Permafrost also benefits vodka because various chemical substances impairing its taste are destroyed during long-term storage inside permafrost, and vodka starts tasting better.
Members of the 1980 and 2010 expeditions placed wheat, rye, oat and barley grains inside the permafrost to see whether they would retain their properties.
"We brought them here, grew them, and they yielded impressive harvests. We also ground wheat and rye grains into fine flour and baked some really safe and high-quality bread," Ulanin said.