Starving off the Land» Sea salt

Salt II

Tamar — Fri, 18 Dec 2009 16:57:36 +0000

Of all the projects we’ve undertaken thus far, I think lobstering is the hardest. Not only does it require a lot of hard, cold, dangerous work, it involves the acquisition of expertise – what kind of traps, where to put them, how to bait them, when to check them. Lobsters are enigmatic and lobstermen are tight-lipped, so acquiring this expertise isn’t nearly as straightforward as learning about, say, gardening. Gardeners will tell you anything.

The slush stage

At the opposite end of the difficulty spectrum is sea salt production. It requires very little work and absolutely no expertise. All we have to do is get some sea water and put it in a pan on top of our wood stove, so it’s hard for me to explain our fascination with the process. The first time we did it, in the dead of last winter, Kevin and I stood in front of the wood stove for minutes at a time, staring at a pan of evaporating water.

We’ve just started our second year of production, and we’re still fascinated. And it’s not just us. People who know us and follow what we’re doing seem to think that our sea salt manufacturing is our most interesting undertaking. Mushroom foraging raises a few eyebrows, but that’s mostly because people think eating wild mushrooms is a benign form of lunacy. Lobstering is old hat to Cape Codders, and chickens only get us a polite smile. But sea salt!

It caught the fancy of my friend Elspeth, who writes Diary of Locavore and does the Local Food Report for our Cape NPR station, WCAI. Not only did she do a radio spot on it (and me, for which I thank her), she tried it at home. Her husband, Alex, is a serious food guy (if you’re ever in Wellfleet, visit Mac’s Seafood), and he reportedly caught the sea salt bug. “He’s been keeping the house at 110 degrees so he can make more of it,” Elspeth said.

I was also recently invited to speak at a gardening forum at Cape Cod Community College, and the organizer emphasized the sea salt portion of the program. “I know you do a lot of things,” Aimee said, “but make sure you talk about the salt.”

In a way, I find this very gratifying. In another way, not so much. “Hey!” I want to say. “I go out on a small boat in lousy weather to haul 50-pound lobster traps up from the bottom of the bay. Don’t you want to hear about that?

In a word, no. It’s all about the salt.

Making sea salt, step one from Tamar Haspel on Vimeo.

“Does it come out gray?” I’ve been asked, many times. The first time I did it, I thought it would, and was very surprised when it dried to a pure snowy white.

“Is it safe to eat?” is generally the next question. I suspect, in the history of the world, nobody’s ever gotten sick from salt for the simple reason that it can’t support life. There are all kinds of microorganisms in the water, but they die as it evaporates. There are other things dissolved in the water – minerals and inorganic compounds – and they don’t go away. If I re-dissolve my salt in water, there is a little residue (mostly calcium carbonate, I suspect), but it’s hard to come up with a scenario in which it’s going to do me harm.

“Can I just boil the water to get the salt?” ask people who don’t have wood stoves. Of course you can, but it doesn’t make sense. Energy is expensive and salt is cheap. This is only worth doing if the energy involved is going begging. If we got more sun, I’d try a solar version in the summer.

The finished product

It’s reassuring to me that we’re not the only ones who find this interesting, but I still can’t put my finger on exactly what it is that holds our attention. It may be that, even though we’ve all known since elementary school that salt dissolves in water, the miracle of something useful materializing out of bucket of water still captivates us.

She steals sea salt by the seashore

Tamar — Mon, 09 Feb 2009 11:34:50 +0000

Sea salt, step one

In New England, the dead of winter doesn’t present many foraging opportunities. I’ve managed, with local assistance, to grub up some chives, bay leaves, and wintergreen, but that’s about it. There is one substance, though, necessary to human life, that we have in abundance here on Cape Cod: salt. We have it in huge quantities, all around us, there for the taking. The only problem is that it’s dissolved in water.

To get at the salt, you have to evaporate the water, a process that requires energy. Since energy is expensive and salt is cheap, this is usually a losing proposition. In the summer, you can employ the sun, but I’m looking for forageable items now, when it happens to be winter. I figured I’d have to put salt on the proverbial back burner until at least June, because if I put it on the literal back burner in February it would be the most expensive sea salt known to man.

Then the light bulb went on. We heat our house primarily with wood and, like just about everyone who heats with wood, we humidify the house by filling a cast-iron pot, designed for the purpose, with water and leaving it on top of the stove. In other words, we’re already in the evaporation business. Why not simply use sea water, and harvest the salt when the water’s gone? Genius!

The standard-issue stove-top humidifier

Kevin wasn’t sold. “So we drive to the ocean, schlep the water back here, store it in the house, keep filling the pot with it, and end up with, what, three tablespoons of salt, retail value seven cents?”

“I think it’ll be more than that,” I said, with more confidence than I felt. How much salt is in sea water, anyway?

How did we answer those kinds of questions before the Internet? Turns out sea water is about 3.5% salt by weight, which means that each liter of sea water should yield 35 grams of it, about an ounce and a quarter. So a gallon should get us at least four to five ounces, a significant haul.

Kevin didn’t believe it. “I don’t believe it,” he said. But he was encouraged enough to participate in the enterprise.

In order to get the salt out of the water, you first have to get the water out of the ocean. To do that, I donned my waders and Kevin and I put our largest manageable container – a four-gallon stainless steel stockpot – in the back of the truck. We headed out to Sandy Neck. Fortunately, it was a cold day, and there were only a couple of people there to watch me wade into the surf, pot in hand, and attempt to get four gallons of water in it while getting none down my waders. The attempt gave “catch a wave” a whole new meaning.

After several inept swoops that bagged a cup or so of water and several pounds of sand, I finally caught a wave in the sweet spot and filled the pot.

I am not at all sure this is legal. I suspect there is a statute somewhere on the Massachusetts books that says that you’re not allowed to remove anything from the Commonwealth’s beaches – no water, no sand, no flotsam, no jetsam. But nobody stopped us, and we took our pilfered water home to evaporate.

To maximize evaporation you want to maximize surface area, and we thought the best vessel for this experiment would be our Le Creuset cast-iron roasting pan. The iron would retain heat, and the 10′x14′ surface would turn our water to salt relatively quickly. We poured the water through a coffee filter to remove at least some of the impurities and critters, and filled the pan.

Our sea salt manufacturing operation

Watching water evaporate should be exactly as exciting as watching paint dry, so I can’t account for the time Kevin and I spent standing around the stove, staring at the water, waiting for the salt to materialize. When the level went down, we refilled it, and watched some more. Again, thanks to the Internet, I knew that water will dissolve 38% of its weight, about ten times more salt than is in sea water. Ergo, when our sea water evaporated down to about a tenth of its volume, I expected the salt to start precipitating out.

You will be happy to hear that the immutable principles of chemistry worked as expected, and when we were down to our last quart and half of water we began to see a thin film of salt form on the surface. That’s when the excitement really reached fever pitch!

Sea slush

The water continued to evaporate, and we started pushing the salt to the edges of the pan. Within twenty-four hours of the formation of the first crystals, we had a pan full of beautiful, snowy-white sea salt. It was just over a pound, which translates to – surprise! – 35 grams per liter.

Kevin is now a believer, and we’re going back to Sandy Neck for another batch; we’ve still got another couple months of wood-stove weather. Come spring, though, we’ll have to be content with watching paint dry.

The finished product