Kinda depends on the agent used (there are quite a few), but it would be complicated. Why not just buy pure salt with no additives or anti-caking agents. They can be slightly more expensive, but it's way easier than trying to make it yourself. You can get chunks of sea salt and grind it yourself (in a large mill, or table shaker size, to grind as needed). Or Kosher salt (pure salt flakes), since they sell it without any additives or anti-caking agents, by kosher rules. Here are a couple links (there are others if you Google for "pure salt no caking agent"): http://wyanjen.hubpages.com/hub/Dont-bless-the-salt And http://www.pureoceansalt.com/pure-ocean-difference.html Hope this helps!