Monday, November 21, 2011

What the Heck is Dendritic Salt? (And a Recipe)

bath salts

Not even spell check seems to know, given the little red squiggly line under “dendritic” as I write this. Despite spell check’s failings, it’s a very useful addition to any homemade bath salts. And bath salts happen to make great gifts. Christmas will be here sooner than you know!

Dendritic salt is a purified form of table salt. The way the salt crystallizes has been modified by the addition of a tiny trace (less than 3 parts per million) of yellow prussiate of soda. That trace is then removed before the crystals are dried. Yes, it’s supposed to be edible, but I don’t think I’ll try it.

Rather than faceted crystals, this process creates star-shaped crystals with micropores in them. And that means lots of extra surface area and more capacity to absorb goodies like essential oils.

Dendritic salt retains more than 2.5 times the amount of volatile essential oils than do regular salts, making it ideal for bath products. Plus, the essential oils don’t evaporate from dendritic salt as quickly, and it doesn’t cause the oils to oxidize (which makes them go rancid).

That extra surface area also means dendritic salt dissolves in the bath more quickly. Finally, that star-shaped structure keeps it from clumping together, improving the flow of any bath salt mixture you add it to.

In commercial products the extremely alkaline trisodium phosphate is often used to prevent clumping. (It’s also added to a lot of breakfast cereals and other foodstuffs, but let’s stay focused.)

The general rule is to use one cup of dendritic salt to 10-20 cups sea salt or other salts. You can buy it and other ingredients from a number of places, including Snowdrift Farm and From Nature with Love.

Here’s a simple bath salt recipe which includes dendritic salt.

Mix together:

  • 2 cups salt. This can be simple sea salt, chunky sea salt, or one of many specialty salts like Dead Sea, Himalayan Pink, Organic Gray, Brazilian, etc. Frankly, I pretty much stick with plain old sea salt, and even kosher salt will work. Don’t use rock salt designed to melt snow and ice, however. I know I probably didn’t need to say that. But I did anyway.
  • 2 Tablespoons dendritic salt
  • 15-30 drops of essential oil. You could use lavender, lavender mixed with basil, rosemary, peppermint, peppermint and eucalyptus, sandalwood, rose geranium, jasmine – anything you’d like. Just make sure it smells nice and that you (or your recipients) aren’t sensitive or allergic to it.
  • If you want a little color you can add ONE drop of food coloring to the dendritic salt first, and then mix that in with the other salt to tint. If you want a deeper color, stick with coloring formulated for soap and other bath products because it’s designed not to stain linens – or people. (Merry Christmas, Sis! Sorry I turned you green!)

You can package your bath salts in attractive glass bottles, or go the considerably less expensive route of clear, cellophane bags tied with a pretty ribbon.

Happy gift giving (and bathing!)


  1. You can decorate your containers:

  2. The correct scientific name for "Yellow Prussiate of soda" is Sodium Ferrocyanide. It is present in dendritic salt at up to 20 milligrams per kilogram and is NOT removed. Also, Sodium ferrocyanide is used in regular table salt (food grade) as an anticaking agent with up to 10 mg per Kg permitted in the finished product as sold on the store shelf. While a few parts per million sounds like a very small amount, 20 mg is about the same as the maximum allowed dose of very many of the ~65,000 medical drugs now on the market.

    Food salt may also contain various amounts of other chemicals and elements including arsenic, lead, cadmium and mercury, The actual amount of sodium chloride (salt) required in the food grade product is no less than 97% salt with the rest being various additives and contaminants. Three percent of a kilogram = 30 grams of something other than salt. These are the official numbers from the Codex Alimentarius Commission that sets worldwide standards for common foods.

    Unfortunately, "pure" sea salt usually contains higher levels of contamination but is not required to be tested. "Sea salt" may contain as much as 15 percent or even more of various contaminants ranging from toxic elements to industrial pollution to that material left by birds flying over the salt pans on the coast.

    A basic rule is that the whiter the salt (sodium chloride) the purer it is but no salt of any type is truly pure.