Originally Posted by Ayrton
Does anyone know why non-iodized salt is recommended for canning, and, thereafter, how crucial it is?
"Canning and Pickling Salt" is pure sodium chloride with no additives.
Additives like Iodine and anti-clumping agents added to table salt will affect the flavor, color, texture and clarity (of the liquid) of things - especially pickled products. Sea Salt contains lots of minerals (in a greater percentage) that can cause the same problems as Iodized table salt.
You can sometimes substitute Kosher salt - but you need to read the label and make sure the kind you buy doesn't have any additives. For example - Morton Kosher salt contains anti-clumping agents (like table salt) but Diamond brand doesn't. I don't know what brands you have available in Greece so I can't help you there - but, with the quantity of olives produced in Greece I'm sure there must be a source.
If you are going to use something other than canning/pickling salt you will need to make adjustments to the amounts called for in the recipe - depending on the type, and brand, of salt you are using.