For best quality home canned foods should be stored in a cool, dry location. Ideally storage temperatures should be between 50°F and 70°F. Canned foods should be protected from excessive heat, from freezing and from dampness. Heat causes food to rapidly lose quality.
All home canned food should be stored well away from direct sunlight, hot pipes, heat ducts, gas or electric ranges and wood heat appliances.
Do not store food in an non-insulated attic. Freezing cold does not cause canned food to lose quality, but may damage the seal on a jar. Remember once a seal is damaged air enters a jar and spoilage begins. Also repeated freezing and thawing may soften food or make it mushy.
If food has to be stored in an unheated area, the jars can be placed in heavy boxes and covered with a clean wool blanket, a very heavy layer of newspaper or a Mylar blanket.
Never store food in a damp area, as dampness may corrode the metal jar lids and compromise the seal.