If a person uses iodized or table salt in there canning pickling and preserving they will often times end up with some nasty looking stuff.
I have seen tight people use it and end up with black looking green beans and nasty looking tomato products.
It is also the reason I dont use it when I cook stuff like beans as it discolors them.
Canning salt is a finer gradual than table salt and table salt has anti caking agents in it too.
I have before me the two salts.
Table salt iodized.
Salt, potassium iodide, dextrose, sodium bicarbonate, yellow prussiate of soda.
Canning salt.
Salt.
I never in my life that I can remember looked at the ingredients of iodized table salt.
I had no idea it had all of that stuff in it.
When I was a kid I could have sworn it was just salt and iodine.
Worth