Do you know how to recognize spoiled food? Sometimes it is obvious... sometimes not.
Botulism is not anything you can see or smell. You will not know it is there until you get sick.
That is another reason to avoid unsafe canning methods. You just won't know it is there. Be confident that your food is safe by using up-to-date canning methods.
Other spoiled food is apparent by just looking at the jars or smelling the contents.
Out of the 250 jars of various foods I canned last year.... I had one that lost it's seal and spoiled. It was a jar of canned whole tomatoes. There was scum on top of the food, the product was bubbly. It was pretty yucky. There was no doubt. I had no problem throwing that one out.
When you take your food out of storage look for these signs of spoilage.
Do NOT taste test any food that you are not sure of!
If in doubt, throw it away!
Before putting jars in storage.
If you notice a failed seal immediately after processing, simply enjoy the foods right away. Store it in the refrigerator just as you would any food.
Storing your jars without the screw lid is a good idea. If the food comes under pressure the seals will naturally break. The seals should not come off if the food is sealed properly and cooked properly.
It is also advisable to store your jars in a cool, dark, and dry environment. Don’t store in a room or area that may contain hot pipes or a furnace. A kitchen pantry is usually just fine.
Direct sunlight will decrease the quality of the foods as well.