Making Salt From Seawater

[_john]

Making your own salt from seawater. Has anyone done this? What is the technique and how can you control the crystal size and texture?

[robert40]

This video may be of some help.

http://www.gourmet.com/diaryofafoodie/vide...ltpepper_fullep

[_john]

I made some salt recently. 2 liters of sea water turned into about 1 cup of salt. The salt crystals are fairly uniform and small. Everyone says that it is not safe to make your own salt because of pollution but I wonder if this is really true. Next time I am going to use a large flat black tray to slowly evaporate it.

[Chris Hennes]

I made some salt recently. 2 liters of sea water turned into about 1 cup of salt. The salt crystals are fairly uniform and small. Everyone says that it is not safe to make your own salt because of pollution but I wonder if this is really true. Next time I am going to use a large flat black tray to slowly evaporate it.

←

Is there someplace you can send a sample of your salt to have it analyzed? I imagine that the safety of your salt will depend on where you got your seawater.

[dougal]

It would be sensible to start with water from a place where the quality is checked.

In Europe (EU) there are designated 'Blue Flag' bathing beaches where analysis of the water quality is posted, demonstrating that the water quality is both monitored and safe.

But in the process of removing the water, we will concentrate not only the salt, but also any undesirable stuff...

Filtering it, as finely as you can, seems a sensible step to start with.

As does boiling it, at least at some stage of the process.

Using solar heating for the bulk of the evaporation saves lots of energy.

The slower you evaporate it, the bigger the crystals.

There may be (purity, flavour, health?) benefits in

- dumping the first crystals/scum to come out of solution

- not evaporating to dryness (dumping the last stuff that hasn't come out of solution)

- washing the collected crystals with brine that has reached saturation

- and baking the final salt in the oven (thats hotter than you'd get in the sun) to ensure that one has dealt with any bio-nasties that might have got through

[helenjp]

Hmmm...it is worth remembering that it's still fairly common in Japan to collect domestic sewage by truck, and stormwater goes untreated into the nearest waterway.

I wouldn't be in too much of a hurry to sample the Inland Sea. On the other hand, beaches closer to the Pacific in Shikoku had very clean water (again, long ago).

If it's considered safe to gather shellfish wherever you got your seawater from, let's assume that you will manage to live through a cupful of salt produced from it!

[slkinsey]

Keep in mind that sea salt is not just boiled-down seawater. All food-grade sea salt must be at least 97.5 percent pure sodium chloride by law. This means that in edible sea salt, at most, you are getting 2.5% "other minerals" and usually a lot less. Salt harvested by solar evaporation, for example, is around 99 percent pure, with the other 1 percent being almost entirely magnesium and calcium compounds. When you evaporate seawater in traditional evaporating pools, some of the stuff you don't want precipitates out before the sodium choride does, so it's possible to get a fairly refined salt. You would not want sea salt that contains everything in seawater minus the water.