The Science Behind The Funny Faces We Make When Eating Sour Candy

Calling all candy lovers! If you had to choose, would you rather go for more chocolatey candy or a sour candy? According to Candy USA, sour candy is surging in growth within the candy market at large, with as many as 120 new sour-based candy items introduced to the market in 2021. This amounted to a whopping $1.3 billion for sour candy alone, marking a 14.9% increase within the sales market.

That's good news for people who actually like sour candy. While some sour candies incorporate the sour flavor directly on the surface, some sour candy confectioners are using more acids to get the flavor. Among these, citric acid, malic acid, tartaric acid, and fumaric acid are the most common choices, all producing various levels of sourness. Because of the versatility of sour flavors, it's no wonder that the creation and innovation of new sour candies are increasing. Some are of course better than others, but if you like the sour-sweet taste, don't hide away from trying some old-school favorites or new candy offerings.

Whether you're accustomed to the sour taste or have it every once in a while, most people unconsciously make a "sour face" when first tasting the flavor. Aside from candy, this also happens when tasting sour fruit, like a lemon. Why is this? There's actually a scientific reasoning behind this.

While the taste of sour is enjoyed by many, it is hard to prevent your face – especially your mouth and scrunching of your nose – from showing the effects of it. So why do we do this when eating anything sour? Humans actually evolved to make this sour face when the flavor hits our tastebuds.

According to USC News, those sour flavors are a result of hydrogen ions that acids release when they combine with saliva. When the flavors hit your tastebuds, it's actually a rejection response from your body trying to tell you, "Hey! This is really sour, and we're not sure about this." Your face naturally scrunches up as a defense mechanism as a form to "protect" you from ingesting these weird foods (via Live Science). 

Back in the day when humans survived on the hunter-gatherer system, non-verbal communication – often expressed through facial expressions – allowed humans to communicate if the food was good or bad (via Mental Floss). If you like sour candy, then you're probably more used to the taste and your face doesn't scrunch up as much as other people's. Again, a method of evolution in the making. To test this, set up a sour candy tasting party with your friends and see who has the most dramatic sour face among the group. You'd be surprised that even those who like sour candy can't resist the urge to make a sour face with some of the most sour candy out there.