You order a dish at a restaurant, but it needs a bit more salt. So, you grab the shaker, only to find there’s rice in there too. This isn’t a mistake—there’s actually a very good reason why there’s rice in the salt shaker.
Salt is prone to clumping because it’s hygroscopic, which is just a fancy word that means it absorbs the moisture in the air. When this happens, the salt dissolves a bit and begins to stick together and to the glass shaker. This is where rice comes in.
Adding a half teaspoon of rice prevents the clumping because rice is also hygroscopic.
“Rice can absorb some amount of moisture preferentially over salt, so that it gets locked inside the rice grains rather than the salt grains,” said Dr. Bryan Quoc Le, food scientist and author of 150 Food Science Questions Answered. “Since rice is mostly starch, it doesn’t dissolve and cling to the salt.”
Plus, rice is too large to come out of the holes at the top of the shaker, so you won’t end up with uncooked rice in your food.
While this practice is common in restaurants, particularly in humid climates with outdoor seating, it’s also a smart idea for your own kitchen. If you keep your salt in a pantry or near your stove—or anywhere steam might accumulate—your salt is likely to clump.
So, grab a bag of rice next time you’re at the grocery store to ensure you always get a perfect pour of salt.