Sour Patch Kids: Acids Taste Sour

• When you first put a Sour Patch Kid in your mouth, it tastes sour.
• The taste is caused by a white powder coating, a mixture of citric acid and tartaric acid.
• The citric and tartaric acids from a Sour Patch Kid combine with saliva in your mouth, and they produce H+ ions. Those H+ ions react with protein molecules on your tongue.
• The protein molecules change shape, sending an electrical signal (a nerve impulse) to your brain that you experience as a sour taste.