Buzz
When you bite into something intensely sour, the reaction goes beyond just your tongue. A strong sour taste can make your whole face scrunch up in discomfort. If you can't help but pucker your lips when tasting a lemon or munching on Sour Patch Kids, you can thank evolution for that.
The unmistakable sour sensation that tingles your taste buds is caused by hydrogen ions released from acids when they mix with saliva. When your mouth detects these acid indicators, it reacts dramatically. Your taste receptors light up, and your face involuntarily twists into what’s called a rejection response, as explained by Live Science.
Your tongue reacts to bitter or spicy foods with similar rejection responses. Many naturally bitter or spicy plants are toxic, and your body’s strong reaction helps keep you safe. While sourness can be found naturally in fruits like citrus, it can also signal foodborne illness in some cases. Spoiled fruits and dairy products, for instance, taste sour due to the acid they contain.
It’s hard to ignore the sourness of your food when it distorts your facial expression. While this reaction might not save you from a bad apple you've already bitten, it could protect those around you. In ancient times, when early humans foraged for food, a sudden grimace may have communicated that whatever was in someone’s mouth wasn’t safe to eat.
The facial reaction to sour flavors helped our ancient ancestors avoid potential illness, yet it doesn’t stop us from enjoying sour foods today. In fact, the desire for sourness is so strong that an entire candy market exists to intensify the flavor in processed treats. So why do we keep eating something that our face and tongue warn could be harmful?
The answer lies in the concept of an acquired taste. Humans don't naturally crave bitter, spicy, or sour foods, but these flavors are key to a healthy diet. Rather than being born with a liking for them, we develop a taste for these foods through repeated exposure. By learning from our peers and family, we gradually identify which sour (and bitter and spicy) foods are beneficial and which ones might be harmful.
Although we use it daily, our sense of taste doesn’t function in the way you might think. Here are some intriguing facts about the sense of taste to chew on.
