The frustration begins when you walk into the kitchen one rainy day to find the same frustrating dilemma – the salt shaker that refuses to release its contents. You want to add seasoning to soup or create a spice blend for the barbecue.
While high-end spice stores recommend expensive airtight containers or silicon-lined containers to tackle this problem, a growing number of homemakers are now relying on an old but proven method that their grandmother used. Add some raw rice grains to the container where you store the salt, and you will not have any problems with clumps anymore.
This is no fairy tale but rather a realistic study of how various natural substances cope with humidity. Salt has a very high affinity for water due to its natural property as a hygroscopic substance, meaning it absorbs moisture from the surrounding atmosphere. The rise in moisture levels makes the surface of salt crystals slightly soft before drying, hence leading to lumps in the salt crystals. The addition of rice makes it possible to control moisture before it comes into contact with your salt crystals.
The science behind the better performance of rice in humidity levels
Why does rice make salt shakers perform better? This is due to the structural nature of rice grains.
This characteristic is examined in the research paper
, published in the journal Scientific Reports. The study highlights how dry rice grains can effectively lower local humidity in contained spaces, acting as a natural desiccant that draws dampness away from their surroundings.
When these grains are mixed with salt, they act as a proactive shield. Because rice has a higher capacity for moisture sorption than the surface of a salt crystal, it intercepts the water vapour first. This relationship is further supported by the study

, published in the journal Food Research International.
In other words, according to the research, only maintenance of the constant water activity can prevent crystalline solid substances like salts from becoming sticky and forming lumps. Rice plays the role of a humidifier in this process, creating a stable internal environment for salt to remain in its crystal form.

Finding the balance in your pantry
Indeed, the use of rice in this case may seem like an innovative DIY idea, but not all types of rice will work. Use raw white rice only; avoid using any rice flour or powders. According to the paper named
, published in Foods, processing rice changes its properties drastically.
Rice flour is prone to becoming sticky or developing rancidity when there is exposure to excessive moisture, which may end up damaging your salt. However, whole grains have a stable structure and do not come into contact with the spices.
To get the most out of this method, start with a clean and completely dry shaker. Add a teaspoon of uncooked rice to the bottom before filling it with your favourite sea salt or table salt. For those living in particularly humid coastal areas or tropical climates, it is a good idea to swap out the rice grains every few months. Over time, the grains will reach their maximum saturation point and lose their "thirst" for moisture. By replacing them periodically, you ensure that your moisture-wicking shield is always at full strength.
In addition to just preserving your salt, it helps you adopt a more environmentally friendly approach to handling kitchen chores. Rather than relying on artificial silica packets, which may not even be food-grade and will eventually end up in landfills, you are now making use of an organic substance that is edible and available to you.
Sometimes, the greatest ideas for the kitchen don’t necessarily come as exciting concepts. The greatest ideas are usually found right before our eyes. By simply understanding the fundamentals of the physics of water absorption by grains, one can control their kitchen environment and protect their pantry items from moisture. Therefore, next time you have trouble with humidity and a clumpy salt shaker, there is no need to buy another device. Just use the power of rice.