Humidity is the enemy of salt. Certainly, you’ve experienced the annoyance of picking up a salt shaker and nothing comes out. You look at it closer and its solidified into clumps. So once again you poke it with your knife to loosen the grains and screw the top back on. Then the next day it happens again.
So where is this humidity coming from? It is certainly weather-related. If its humid outside, it will be humid inside. Of course, air conditioners can offset some of that but the effectiveness will vary between models. Salt kept in the kitchen also has continuous exposure to steam from cooking. And finally, think about where the salt is kept. It is inside a shaker with holes at the top. Perfect for introducing moisture.
Now that we know where the moisture is coming from, why is it forming clumps in the salt? The short answer is that salt is hygroscopic. This means it absorbs water vapor which then dissolves the salt grains thus causing them to group together. The result is salt clumps in your shaker.
For generations, people have been using various methods to stop the clumping in their salt shakers. Utilizing different herbs, grains and containers in their quest to stop the clumping.
For example, chopping parsley is one strategy. It is added while fresh and as it dries out in the bottle it eventually absorbs the moisture. Unfortunately, it also changes the flavor of the salt. As lovely as it sounds, not everyone wants parsley flavored french fries.
Using a different container sounds reasonable. Find one that seals and the moisture won’t get in. Perhaps a mason jar or a salt cellar. However, you will eventually have to open it. After opening, how long will it remain open? If you are cooking or eating it may stay open for a while. Remember, cooking creates humidity so the salt has now been exposed to moisture.
Grains seem to the popular choice. Especially rice. While popcorn is sometimes an option, it’s not very visually appealing. Not to mention it’s large and may not fit well with some shaker designs. Rice will blend in nicely with the salt and even after noticing it’s not worth mentioning.
Using rice in a salt shaker is easy, but there are many types to choose from from. The consensus seems to be on the side of long-grain rice. Place it in the shaker and your clumps will be gone.