I have not used regular salt or non-iodized salt in quite some time. But honestly, you can add salt any time you want, up to and including in the glass when you drink the beer! Some people add a pinch of salt to every glass and enjoy it better that way. Otherwise, typically it is probably added either in the mash tun or in the kettle. It really doesn't matter. If you think you need salt, add some to taste, whenever you want. Personally I don't do much with salts anymore, but of course feel free to play around with it and see what YOU like best.