The Reason Sour Candy Makes Your Tongue Hurt
The urban legend that child-hating jerks are passing out Halloween candy with hidden needles and razor blades has largely become a nothing more than a myth at this point. A far more disturbing possibility is the idea that those extremely sour Warhead candies might burn a hole into your tongue (via Dayton Daily News). Um, no thank you. Sour candies are supposed to make your lips pucker up, but burns shouldn't be part of the deal.
Reports began circling in 2015 that kids were suffering from burned tongues from eating too many sour candies (via Vice). That's certainly a little more concerning than a mere cavity. So why exactly can sour candy leave our tongues with a burning sensation?
The science of the sour candy burn
Whether it's that box of Sour Patch Kids you overpaid for at the movie theater concession stand, or a single Warhead candy you popped in your mouth on a dare, all sour candy has similar components that add to its sourness. Basically, it's acid that makes sour candy sour. You'll find citric acid naturally in fruits like lemons, limes, and grapefruits, and the hydrogen ions in the acid tap directly into our "tongue's sour taste receptors" (via Wired).
Some sour candies stay sour longer than others though, and this is because manufacturers add malic acid coated with hydrogenated palm oil. The sweetness of the oil gradually melts away in your mouth and the acid takes over to work its mouth-puckering sour torment magic. As for the reason your tongue might hurt while gobbling down sour candies, well, that would be the acid. Acid is corrosive. It's why if you eat a full pineapple in a single sitting you might develop a few canker sours inside your mouth. The same is true for the malic and citric acid in sour candies, and the soft flesh of your mouth can only take so much irritation.
The good news is that there's nothing wrong with enjoying a few sour candies now and then and that burn will eventually fade. Unless you want your tongue to feel like it just got a deep clean from a Brillo pad, though, go easy on the stuff.