About a year https://desolmed.com/equipment/stmap_5347zes.html?diarex.dexamethason.adalat.cialis supplementdesigns.com  A: It's less than a decade old. Its discovery is a little shrouded in mystery. I think there was some opportunistic cooking maybe on salt stones in ages past. But in terms of salt-block cooking the way we think of it now, all evidence I have is that it's an American invention.