Sour candy might taste great in the moment, but the high acidity can do some damage to your tongue. Sour candies contain citric acid or malic acid, which give them that tart, puckering flavor. These acids activate the pain receptors on your tongue, which leads to the stinging sensation. The acids in sour candy are harmless in small doses, but eating too much at once can irritate your tongue.

The acids in sour candy strip away the protective coating on your tongue called the epithelium. This layer of cells protects the sensitive taste buds on your tongue. When the epithelium is damaged by the acids, your taste buds are exposed to the environment in your mouth. This exposure leads to the pain and sensitivity. The damage is temporary, but it can be uncomfortable for a while.

Your saliva contains bicarbonate, which helps neutralize the acids in your mouth and protect your teeth. But when you eat sour candy, your mouth produces extra saliva to try and balance out the pH. This extra saliva, combined with the damaged epithelium, leads to the swelling and stinging pain in your tongue. The pain should subside once the acids have been washed away and your tongue has healed.

Drinking water or milk can help relieve the stinging faster. These liquids help dilute the acids in your mouth and wash them away from your tongue. Swishing the liquid in your mouth and spitting it out a few times may provide even more relief before swallowing. Avoid brushing your teeth immediately after eating sour candy. Brushing can further damage your already irritated tongue.

The pain from sour candy should only last a few minutes up to an hour at most. If your tongue remains swollen, stinging or irritated for longer than a day, you may have a sensitivity or allergy to an ingredient in the candy. See your doctor if the pain is severe or long-lasting. They can determine if further treatment is needed based on the condition of your tongue.

In the future, enjoy sour candy in moderation and avoid overeating it at once. Give your tongue adequate time to recover between doses of extreme sourness. And remember, the pain is only temporary—your tongue will heal and the sensitivity will fade, though the memory of that tangy sweet and sourness may linger.