So your vegetable garden didn’t do so well. You only got a measly few quarts of home grown veggies to put by. Now it’s the depths of winter and you need some summer veg to make a nice stew. But, oh no! There’s some mold on there! Oh, well, you can just scrape it off, right?
STOP. Stop right there.
Even foods which are considered acidic enough to not need a pressure canning experience – such as tomatoes with added lemon juice or citric acid – can become perilously high in pH if mold grows in there.
Why is the acidity and a proper seal so important? Because if the acidity falls too low, Clostridium botulinum will grow in there. C. Botulinum is the bacterium that produces the botulinum toxin as part of its metabolism. This is what causes the deadly illness called botulism. If you come down with botulism and do not receive immediate emergency medical care including artificial respiration, there’s around a 70% fatality rate.
If your preserved food shows any signs of not being preserved properly – mold, bulging lids, bad smell, sliminess – immediately destroy the food such that it cannot be eaten by humans or animals – give it a hard boil for 15 minutes, then flush it down the toilet.
Whatever you do, do not take any chances with your health or the health of any loved ones (human/furry/feathered/scaled). It really is not worth it.