Cooking salt от John Spottiswood

Varieties include iodized salt, which contains the flavorless additive potassium iodide to prevent goiter (an enlargement of the thyroid gland), and non-iodized salt. Some recipes call for non-iodized salt, since iodine can impart a bitter taste and adversely react with certain foods. For example, iodine darkens pickles and inhibits the bacterial fermentation needed to make sauerkraut. Table salt also contains small amounts of calcium silicate, an anti-caking agent, and dextrose, a stabilizer. The anti-caking agent in both iodized and non-iodized salt doesn't dissolve in water, so if you pickle or can with it, it will turn the liquid cloudy or else settle on the bottom of the jar. The preserved food will taste the same, mind you, but it won't look as appealing. This is more of a problem for pickles, which are immersed in lots of liquid, than for other canned goods. To prevent the cloudiness, use pickling salt, which contains no additives.