Some salt (table salt) has additives like iodine or anti caking agents that you don't want in your ferment because it will cause it to be cloudy (or even more cloudy).
There's also some people who claim the iodine will inhibit fermentation, but studies have shown that it doesn't have much of an effect [1].
Kosher salt contains an anticaking agent. My box of Morton Kosher salt list Salt and Yellow Prussiate of Soda (anticaking agent) and so does my box of Windsor Kosher salt.
Oh you're right! I've got a box of coarse salt as well and it doesn't have any additives - interesting as it and the kosher salt are about the same size.
In North America, the coarse salt with zero additives is called "kosher" salt because the Jews used it to brine meat. It's generally approved by a Rabbi but even if it weren't actually Kosher, it would still be called kosher.
I read some time back about an article (and wish I had bookmarked it) about the "types" of salt. That particular one classified [non-millable] salts into three different categories.
Table salt: the fine, iodine-added salt you get in plastic bottles. Comes with anti-caking additives to prevent clogging.
Finishing salt: large flakes of sea salt, mostly used by professional kitchens to add the final touch to a dish.
Kosher salt: a sort of catch-all name for salt without additives, more coarse than table salt but small and granular enough to roll off of an unsuspecting surface.
Based on what I use personally, I think both of my choices fall between the last two categories. Maldon sea salt for most cooking uses (disregard the brand, Maldon just happens to be plenty available in the UK), and extremely coarse sea salt / rock salt for filling the mill. The sea salt flakes are fine enough to crush easily between the fingers, so in practice it probably behaves much like you'd get from a "kosher salt".
there's also other salts in it besides sodium chloride. for some reason my brain tells me that pink salt is saltpeter, but that's potassium nitrate, and wikipedia says pink salt is sodium nitrate.
Close. When I was a kid we used to make gunpowder (charcoal, sulfur, potassium nitrate) with saltpeter that we got from the drug store. The story to tell was "my mom is making ham." But that was whitish.
Hmmm. I do have some pink salt that I used to cure ham last fall. OK, just checked and the package says sodium nitrate.
mostly to avoid any iodine which could interfere with the fermentation process. I suppose one could use pickling salt too. Maybe regular table salt is fine, but that's what I use since I keep it on hand.
Kosher, in this sense, describes the texture of the salt (coarse-grained), not necessarily that the salt is kosher in and of itself (though it usually is).
