In the food world, salt is kind of a superhero. Without it, french fries are bland, potato chips are boring, and chocolate chip cookies lose their pop. And that’s because salt doesn’t just make things salty—it has lots of effects on flavor perception. In fact, if you’re thinking about using a spoonful of sugar to help the medicine go down, a pinch of salt might actually work better.
At the most basic level, humans like salt because we need it to survive. Salt as we know it—which is usually sodium in the form of sodium chloride—is an essential nutrient. You use sodium ions for everything from communication between your neurons to managing your blood pressure.
Your body can’t just make sodium from scratch. So, you have to get at least some from your diet. And since there isn’t usually much salt lying around unless you live near the ocean, it makes sense that we evolved a taste for it to make sure we get enough.
In 2010, researchers confirmed that we mostly taste saltiness thanks to epithelial sodium channels, which are basically pores that let sodium ions into the taste receptor cells in your taste buds. Those cells then signal your brain that something’s salty.
But, weird as it might sound, salt actually makes things sweeter because it reduces your perception of bitter flavors. Studies have found that salt is actually better at reducing bitterness than sugar. Scientists don’t have the mechanism for it completely figured out, but research suggests it involves both your tongue and your brain.
Most of the bitterness-blocking happens in your taste buds, where it’s thought the sodium might interfere with the binding between bitter compounds and their taste cell receptors. Salt also reduces other unpleasant tastes, so flavor chemists think it influences other taste cells too. Somehow.
Researchers have also found that if you’re given salt and a bitter compound in such a way that they don’t mingle on your tongue, you still perceive the overall flavor as slightly less bitter. That suggests some of the anti-bitterness effect comes from how your brain interprets multiple taste signals when they include saltiness.
Salt may also enhance sweetness more directly. We know that in mice, at least, one of the proteins that pulls sugar into taste receptor cells can’t do its job without sodium. So a dash of salt could mean an extra burst of sweet. Salt can also make things taste better by making them smell better.
When you add salt, its ions are attracted to some of the available water in the food. And that makes it easier for volatile compounds — molecules that evaporate quickly and often contribute to something’s aroma — to escape into the air. Those compounds may not hit your tongue, but they still contribute a lot to your perception of flavor.
Salt also seems to do other things to make food more enjoyable … although scientists can’t really explain them yet. For instance, volunteers in a 1985 study said salted split pea soup was not only saltier, sweeter and less bitter than the unsalted version, it was also thicker and fuller, altering what food scientists call mouthfeel. That one single ingredient transformed the whole dish!
So, if you’re not happy with your dinner, there’s a good chance that reaching for your salt shaker will help. But if you’re in the mood for more than just plain old regular salt, you can also infuse salt with flavor to make your meals even more exciting.