How to Prevent Salt from Caking

Earlier this week my Kosher salt was not flowing easily out of its shaker.  Hardly a major catastrophe, but a sign that I had forgotten one of my favorite tips from my own mother.  She always put a few grains of rice into her shaker to prevent the salt crystals from “caking” or clumping together.

Remember when I used a bag of rice to bring my wet iPhone back to life?  The principle is the same – i.e. rice absorbs moisture.  Putting a few grains of rice into a shaker doesn’t affect the salt crystals, it just prevents them from attaching to each other.

So why hasn’t my table salt caked in its shaker when my Kosher salt did?  My table salt (Morton’s iodized salt) contains an anti-caking agent, calcium silicate, while my kosher salt (Diamond Crystal) does not contain any additives.  By the way, sea salt (I have both fine and coarse) usually does not contain anti-caking additives.

The addition of a caking agent is FDA-regulated and I am not worried about the safety of the small amount of table salt I use.  (Other common anti-caking agents used in table salt besides calcium silicate are sodium silicoaluminate, magnesium carbonate, and tri-basic calcium phosphate.)  Still, it’s interesting to note that even when I’m not using prepared foods, there may be additives I haven’t noticed in the food I prepare.  

What type of rice to use in a shaker of Kosher salt?  If you use “regular” rice, the grains are so thin (compared to the grains of kosher salt) that they will probably slip through the holes of your shaker.  I used Arborio rice and it worked like a charm.

I realized that my sea salts haven’t caked and neither has the Kosher salt cake left in its large cardboard container. Why?  I think those containers are so large that when using them, I end up shaking the salt without realizing it.  And if the salt in those containers does cake, I’ll know what to do – thanks to my mother.