When a rumor circulated on Twitter this week that Diamond Crystal kosher salt was being discontinued, cooks who were used to seasoning with it became remarkably anxious. A few fans even stocked up on the red-and-white boxes, just in case.

“I didn’t pay it too much mind at first, because I couldn’t process a world where this would happen,” said Francis Lam, a cookbook editor and the host of the radio show The Splendid Table. “But a handful of people kept talking about it.”

So Mr. Lam left work early and bought 10 three-pound boxes of the salt at his local grocery store in Brooklyn, then carried them half a mile home. “Taking no chances,” he wrote on Instagram.