Most people who start making their own bath salt don’t know about this “secret” ingredient, but it’s really useful.  If your bath bombs or salts aren’t retaining their fragrance, or your essential oils are going bad in your dry products, you might want to try dendritic salt. Dendritic salt is just like plain old table salt, but it absorbs more than twice as much fragrance – and prevents it from escaping or going bad as fast.

Why dendritic salt can absorb more than table salt.

Same ingredients, different growing process. During the manufacturing (yes, dendritic salt is lab-made), a trace of “yellow prussate of soda” is added to the sodium chloride, making the crystals grow in a star-shape. This means that each of the crystals has more surface area.
Dendritic salt helps your bath salts and bombs have a longer, more fragrant shelf life.

This is especially important if you use essential oils, because those deteriorate. They have a half-life. According to the chemist from Snowdrift Farm, the magnesium salts found in sea salts and Epsom salts make your essential oils oxidate – they break down and go rancid, and this probably means they lose their fragrance (or smell bad.)
Dendritic salt recommended amount: 5% – 10% of dry ingredients.

5% to 10% dendritic salt is the recommended usage, but you can use more that that. After all, it’s just salt! Dendritic salt is very fine and moisture-absorbing, so it resists caking and clumping. For bath salts, amount isn’t that much of an issue since it won’t affect the overall structure of the product.

But for bath bombs, you can only add so much before it starts to affect the hardness and, ahem, “structural integrity” of your fizzies, especially with additional ingredients such as corn starch and moisturizing oils. You’ll have to test – but it may help with high-humidity problems since it’s so absorbent.
How to use dendritic salt in your bath salts or bath bombs.

It’s easy! Just mix your fragrance or essential oil in the dendritic salt first. The dendritic salt will trap and hold the oils when it’s mixed in with your bath salts or bath bomb mixture. Of course, this means that your products won’t smell quite as strong, since the salt prevents the fragrance from evaporating. Don’t be fooled and immediately start adding more fragrance – the scent from your bath salt or fizzies will release fully when dissolved in water.
Where to find dendritic salt.

Not the grocery store, probably – dendritic salt is mostly used as a non-edible item. But the good news is that all the major bath and body online suppliers have it. MMS, From Nature With Love, Bramble Berry, Coastal Scents all have it, so next time you place an order, put in a pound or two of dendritic salts to play with.