Monday, January 26, 2015

Grain Mill Strikes Again: Grinding Sea Salt

We ran out of store-bought salt the other day, right before we were about to do some baking.  We had some big salt rocks in one of those hand grinder things (like the kind that the waiters use to grind pepper onto your salad at fancy restaurants like Olive Garden), but when we're baking and we want a teaspoon of salt, it's hard to tell how much we've ground up.  It's much easier if we have a container of pre-ground salt that we can take from.  So, we got our grain mill out again this weekend to take our salt rocks and turn them into salt grains.  (For what it's worth, we've now used our grain mill on eggshells, sugar, and salt, but not yet grain!)

This is part of a batch we collected off Mount Desert Island in Acadia National Park, Maine.  From one gallon of sea water, we got about 75 g salt (around half a cup).  Since the salinity of seawater in that area is 31-35 g/L, we should have gotten ~118-133 g of salt, so our yield is curiously low, unless we used some of it for other stuff we can't remember. (Which is totally possible.)  We dried it in a 9 x 13" pan on top of the fridge, and finished it off in the oven.  Kind of cool to watch the crystallization process.  In an earlier batch, we dried driving off the last of the water in a plastic container in the microwave.  DO NOT do took less than ten seconds for the plastic to melt and stink up the kitchen!

Anyway, the granules here are much bigger than we'd like.  In the photo, we're trying to sieve it after grinding it with a mortar and pestle.  The old M&P didn't work very well for the single crystal chunks.

But those crystals are no match for the grain mill!

When all was said and done, we had a nice bowl of white powder. Our home-dried sea salt stuck in the mill a little more than the other salts we tried (we found a container of large-grained pink Himalayan salt in the cupboard also), so maybe we didn't get it quite as dry as we thought we did.  [Ooh!  Here comes Katie!] Hey Katie, grab a spoon!  Want to try some of this fresh-ground sugar?

Post-grinding, back into the canning jar from whence it came.  We made sure to clean up the grain mill real good afterward because chloride ions and steel don't get along very well.

One other bit of info we discovered while following our curiosity on this post is that sea salt doesn't have much iodine in it. (i.e., it's I content is way lower than iodized regular salt.)  That's kind of disappointing because we were hoping that if we took a trip to the ocean once a year or so to make our own sea salt, we wouldn't have to buy salt at the store and could still avoid catching the goiter (or other iodine-deficiency disorders).  But it looks like we'll have to collect the seaweed and fish, too, to make that happen.  Or eat plenty of cranberries, which seem* to have a high iodine content despite being mostly grown in the middle of the goiter belt.  Possibly because the region they're grown in has a high organic matter content in the soil, which is very good at capturing atmospheric iodine (e.g., as CH3I) and storing it in a plant-accessible form.

*Many online sources claim that cranberries have up to 400 ug iodine per 4 oz serving, but we couldn't find the original source of that number.  A paper from 1928 gives a value of 35 ppb iodine (ppb = ug/kg), which works out to 3.97 ug iodine per serving:

Wethinks someone may have done a faulty conversion of units along the way, which was then propagated by less-than-diligent authors.  Another reminder to take internet-based information with...a grain of salt.  A more recent source gives 100 ug I /kg cranberries, or 11.3 ug/serving, which is on par with eggs, freshwater fish, and other fruits--and still nothing to sneeze at, accounting for ~7.5% of the recommended daily intake (RDI).  Since three cups of cranberries = 12 oz, at that rate, all you'd need is 2.2 pans of yuletide strata per day to completely satisfy your iodine RDI!

 How do you cover your salt (and iodine) needs on the homestead?  Let us know in the comments section below!

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