With home canning, food safety is first priority. Although food poisoning from home canning is uncommon it is important not to eat if a seal becomes broken or the lid is bloated. It is normal for the color to fade after a number of months, but if the jam is not even in color, or new specks are noted in a stored jar, do not eat. Jam is very shelf stable and this is not likely to happen, but always remember to look first, and then eat.