This has to be the coolest thing I’ve ever found growing in my basement. Fermented things, as you probably already know, require a lot of salt. To make sauerkraut, for instance, you mix approximately 4 1/2 T of kosher salt per 5 pounds of cabbage, stuff everything into a jar, and weight it until the cabbage is submerged in its own brine. Weight 3 to 6 weeks, and you’ve got sauerkraut.
Sometimes, fermentation gets messy. Your jars leak and leave little salty puddles on the floor. And because the basement gods were smiling, I got crystals instead of scum and mold. And although I do know that there’s a perfectly reasonable scientific explanation, I’m happy to chalk this one up to magic.