Why Do Sour Candies Make Your Mouth Pucker?

Even if you aren't a candy lover and didn't grow up eating Sour Patch Kids, Lemonheads, and Warheads, you've undoubtedly tried something sour and know the feeling of your entire face squishing once the flavors hit your taste buds. Some sour things are a little less pucker-inducing, like a whiskey sour that balances the sour citrus with smokey whiskey (and is surprisingly easy to perfect). Others, like a piece of grapefruit or slice of lemon, are a bit more pronounced, but we still love them.

The reason these things cause you to recoil in a mixture of disgust and delight is simple: acid. The acidity in certain foods interacts with your taste buds, which send a warning signal to your brain that results in a completely involuntary reaction — our faces pucker. Our bodies react in such a strong way as a natural response to something that could hurt us so that our brains can make informed decisions about whether or not something is safe to eat.

These acids, specifically the citric acid of citrus fruits, the malic acid of apples, and the tartaric acid in fruits like grapes, are something candy makers have learned to use to their advantage. In fact, you can use citric acid to turn dried fruit into a tastier treat. Candy makers are on to this secret and use it to make candies that are sweet, sour, and full of delicious flavor underneath the burn.

It's no secret that we love eating sour candies, especially as kids, when eating things that cause the burning, stinging, face-puckering response creates both a physiological and a psychological response. As a kid, it's a way to prove yourself and show off for your friends that you can handle it. The sourer, the better. As adults, it brings up a sense of nostalgia. For both kids and adults, tasting something super sour creates a dopamine rush to the potential threat our taste buds perceive, but the sour taste in candies is also usually mixed with yummy flavors like apple, lemon, and raspberry. Those delicious tastes, combined with a whole lot of sugar, create an experience that allows us to associate that sour reaction with a variety of things that kids love for a positive experience — when you like something and know there is a sweet ending, proving you can handle it doesn't feel like so much of a challenge.

Sour foods have been a human obsession throughout history, dating back to the ancient Egyptian and Greek civilizations. As society has evolved, the fascination we have with sour flavors and the love we have of pushing our physical limits has certainly not waned, and sour candies are the perfect outlet for feeding this desire, as evidenced by the massive value of the sour candy industry (Industry Arc projects the sour candy market to grow to $2.7 billion by 2030).