Sensing that we had room for improvement in our salt-making efforts, we sent a sample of our salt to Mark Bitterman, author of the recently published Salted and the “selmelier” at The Meadow in Portland, OR. He seemed generally impressed that we had made our own salt with water straight from our local patch of ocean. However, he did mention right off the bat that our salt was “really high in aluminum, probably from the baking trays that are being used.” I had suspected that the slightly gray color was from the trays, and now I knew for certain.
Mark suggested we use glass or Pyrex for baking the brine, since both are inert materials. I’m actually a bit embarrassed that I didn’t think of this myself.
I poured fresh ocean water into a few 9- by-13-in. Pyrex pans, using the same quantities and oven temperature as I had before, and otherwise following the same method. This time, the salt was snowy white. It was also easier to scrape off the pan, requiring more of a firm wipe than the kind of a muscular, metal-on-metal scratch job than I had to use with those aluminum sheet trays.
I sent a sample of the Pyrex salt to Mark. Here’s what he said:
"The salt has a lovely opaque, crème fraîche color that comes from an abundance of the sea's trace minerals. The crystals are marvelously diverse in form, ranging from finely fringed micro-grains to layers of laminated flakes. And the flavor: a roiling oceanic assault on the senses--only nice, like being caught in a wave of sun-warmed water, briny and bitter and butter-sweet. This is certainly a great all-purpose cooking salt, but is also wonderful for finishing dishes, sprinkling a little on top of your food just before eating it."
We agree! And we’re sprinkling it on everything now.