Characteristics Of Dendritic Salt
Dendritic salt has special properties making it very useful in the making of soaps and bath salts, whether commercially produced or produced in the home. The term dendritic has to do with the shape of the salt crystals, and not with the chemical makeup of the salt, which is simply sodium chloride, table salt if you prefer.
The word dendrite comes from the Greek and means tree-shaped of having branches, In the case of dendritic salt, the branches form what are essentially snowflake patterns. Dendritic salt is very finely ground salt, almost ground to a powder, with the individual crystals usually too small to be seen by the naked eye. A good example of a dendrite or dendritic pattern can be seen on a window on a frosty day. Many crystals, including metal crystals, have dendritic patterns. Most salt crystals consist of small cube-shaped forms, making the snowflake-like dendritic salt crystals somewhat of a novelty.
It's All In The Pattern - It is the snowflake pattern that gives dendritic salt its most useful properties. The snowflake pattern contains a much larger surface area than does a cube-shaped crystal containing the same amount of salt by weight. This larger surface area allows the salt crystal to absorb a much greater amount of water before dissolving. It will also absorb a much greater amount of oil, making it particularly useful in bath salts and bath oils, as it tends to hold fragrances much tighter. The crystalline shape of dendritic salt also makes it more resistant to clumping.
Dendritic salt usually isn't used exclusively in the production of bath salts or soaps. It is usually mixed in with coarser crystals of salt at a ratio of approximately one part of dendritic salt to 20 parts of the other type of salt, a 5% mixture. When making perfumed bath salts, the essential or fragrance oils are usually mixed with the dendritic salt first, and then the dendritic salt is mixed in with the other salts.
Manufacturing dendritic salt requires using sodium chloride that is exceptionally pure. Salt crystals are grown under carefully controlled conditions during which trace amounts of yellow prussiate of soda are added to force the crystal growth into the desired snowflake pattern. The resulting salt crystals are incredibly pure formations of sodium chloride, with each crystal containing many branches and each branch containing a number of small pores, leading to the high absorptive capacity of the salt. This absorptive capacity is also responsible for the reduced volatility essential oils and fragrances have once combined with the salt. The physical makeup of dendritic salt also makes products using the salt more stable and hence contributes to a longer shelf life. Finally, when used with essential oils and fragrances, the salt keeps the oils from oxidation, and as noted before, greatly reduces their volatility.
Inexpensive, Relatively Speaking - Dendritic salt is easy to purchase if one looks to retailers specializing in supplying soap or bath salt manufacturers or home soap and bath salt makers. It is not terribly expensive in the sense that only a small amount is usually needed to produce a large amount of the desired item. It can retail for around $5 a pound, which admittedly is more expensive than table salt. However, when you consider that if you want to make your own bath salts, you can add adding lavender oil to some dendritic salt and add that mixture to two cups of coarser salt, such as Dead Sea salt. The amount of dendritic salt required would be 2 teaspoons, so a pound of it will go a long, long ways.