Don't see why boiling would effect anything other than any live organisms in the brine. CaCl is just dissolved salts, can't go anywhere or turn into anything else. I recently attended a workshop where a cheesemaker from a small cheese factory spoke. They save their brine forever, and heat it (not quite boiling, like 170-something, aka pastuerizing) every few months. I would always sprinkle salt on the top surface of my cheeses brining, until I realized I had 1-2 inches of salt crystals settled on the bottom. As long as there is some crystal salt, the brine is essentially saturated. Over time, it is also becoming more an more closely matched in composition to the cheeses (Calcium and mineral content, etc), for the better.