Photo: Penn State University
So you’ve put a lot of work into canning food at home, but still find a jar or two that has mold growth. Is it safe to eat?
Mold growth in foods can raise the pH of the food. In home canned products, this could mean that the high acid products could become low acid and therefore run the risk of botulism or other bacterial spoilage. Thus, any home canned product that shows signs of mold growth should be discarded.
USDA and microbiologists now recommend against even scooping out the mold on jams and jelly products and using the remaining jam or jelly, even though that used to be suggested.
Source: https://nchfp.uga.edu/questions/FAQ_canning.html#15
