All salt, being a rock and not organic material, is technically kosher. The term “kosher salt” refers to the salt preferred by kosher butchers, which has a fluffy texture for superior absorbency. This salt does not contain iodine, making it ideal for canning and preserving (make sure to measure by weight rather than volume, as this salt is much lighter than granular salt). This inexpensive Kosher salt is wonderful for everyday use, with a flavor and texture nice enough to use as a finishing salt. No additives. Available in 3 pound box only.
See a video of The Spice Boss explaining what makes salt kosher.