Boulder Salt’s ingredients are determined by purity, not by location. Boulder Salt only uses products that are USP, pharmaceutical grade, or higher. You’re correct on calcium carbonate, but it is not as soluble as other forms of calcium. The first aim in creating a low sodium salt that behaves like salt was that it had to be delicious. Salt on the market is not popular. It’s a bitter taste that comes from soluble calcium. Formulating is a balancing act, and we had to choose if we wanted savoury tasting salts or one that provides merely hints at ice.
